spi: spi_flash_probe_bus_cs() rely on DT for spi speed and mode

Now, spi_flash_probe_bus_cs() relies on DT for spi speed and mode
and logically calls spi_get_bus_and_cs(). In case spi mode and speed are
not read from DT, make usage of spi_flash_probe() instead.

To sum-up:
 - Previous call tree was:
    spi_flash_probe() -> spi_flash_probe_bus_cs() -> spi_get_bus_and_cs()

 - Current call tree is:
    spi_flash_probe() -> _spi_get_bus_and_cs()
    spi_flash_probe_bus_cs() -> spi_get_bus_and_cs()

This patch impacts the following :
  - cmd/sf.c: if spi mode and/or speed is passed in argument of
    do_spi_flash_probe(), call spi_flash_probe() otherwise call
    spi_flash_probe_bus_cs().

  - drivers/net/fm/fm.c: as by default spi speed and mode was set to
    0 and a comment indicates that speed and mode are read from DT,
    use spi_flash_probe_bus_cs().

  - drivers/net/pfe_eth/pfe_firmware.c: spi speed and mode are not read
    from DT by all platforms using this driver, so keep legacy and replace
    spi_flash_probe_bus_cs() by spi_flash_probe();

  - drivers/net/sni_netsec.c : spi speed and mode are not read from DT,
    so replace spi_flash_probe_bus_cs() by spi_flash_probe().

  - drivers/usb/gadget/max3420_udc.c: Can't find any platform which make
    usage of this driver, nevertheless, keep legacy and replace
    spi_get_bus_and_cs() by _spi_get_bus_and_cs().

  - env/sf.c: a comment indicates that speed and mode are read
    from DT. So use spi_flash_probe_bus_cs().

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>

Cc: Marek Behun <marek.behun@nic.cz>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Vignesh R <vigneshr@ti.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Stefan Roese <sr@denx.de>
Cc: "Pali Rohár" <pali@kernel.org>
Cc: Konstantin Porotchkin <kostap@marvell.com>
Cc: Igal Liberman <igall@marvell.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Pratyush Yadav <p.yadav@ti.com>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Anji J <anji.jagarlmudi@nxp.com>
Cc: Biwen Li <biwen.li@nxp.com>
Cc: Priyanka Jain <priyanka.jain@nxp.com>
Cc: Chaitanya Sakinam <chaitanya.sakinam@nxp.com>
diff --git a/cmd/sf.c b/cmd/sf.c
index 8bdebd9..8713736 100644
--- a/cmd/sf.c
+++ b/cmd/sf.c
@@ -91,6 +91,7 @@
 	unsigned int speed = CONFIG_SF_DEFAULT_SPEED;
 	unsigned int mode = CONFIG_SF_DEFAULT_MODE;
 	char *endp;
+	bool use_dt = true;
 #if CONFIG_IS_ENABLED(DM_SPI_FLASH)
 	struct udevice *new, *bus_dev;
 	int ret;
@@ -117,11 +118,13 @@
 		speed = simple_strtoul(argv[2], &endp, 0);
 		if (*argv[2] == 0 || *endp != 0)
 			return -1;
+		use_dt = false;
 	}
 	if (argc >= 4) {
 		mode = hextoul(argv[3], &endp);
 		if (*argv[3] == 0 || *endp != 0)
 			return -1;
+		use_dt = false;
 	}
 
 #if CONFIG_IS_ENABLED(DM_SPI_FLASH)
@@ -131,14 +134,18 @@
 		device_remove(new, DM_REMOVE_NORMAL);
 	}
 	flash = NULL;
-	ret = spi_flash_probe_bus_cs(bus, cs, speed, mode, &new);
-	if (ret) {
+	if (use_dt) {
+		spi_flash_probe_bus_cs(bus, cs, &new);
+		flash = dev_get_uclass_priv(new);
+	} else {
+		flash = spi_flash_probe(bus, cs, speed, mode);
+	}
+
+	if (!flash) {
 		printf("Failed to initialize SPI flash at %u:%u (error %d)\n",
 		       bus, cs, ret);
 		return 1;
 	}
-
-	flash = dev_get_uclass_priv(new);
 #else
 	if (flash)
 		spi_flash_free(flash);