PowerPC: Rework PBL location choice

When converting CONFIG_SDCARD and CONFIG_SPIFLASH to Kconfig, one set of
uses wasn't converted correctly. Allow for the case where platforms
don't rely on "PBL" to boot but instead use other mechanisms. See the
link below for more details.

Link: https://lore.kernel.org/all/20220802091338.f4g45ldhc7qbg6hm@pali/
Fixes: d433c74eecdc ("Convert CONFIG_SDCARD et al to Kconfig")
Tested-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/boot/Kconfig b/boot/Kconfig
index 4a001bc..424ad0e 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -724,16 +724,19 @@
 	  For more details refer to doc/README.pblimage
 
 choice
-	prompt "Freescale PBL load location"
+	prompt "Freescale PBL (or predecessor) load location"
 	depends on RAMBOOT_PBL || ((TARGET_P1010RDB_PA || TARGET_P1010RDB_PB \
 		|| TARGET_P1020RDB_PC || TARGET_P1020RDB_PD || TARGET_P2020RDB) \
 		&& !CMD_NAND)
 
 config SDCARD
-	bool "Freescale PBL is found on SD card"
+	bool "Freescale PBL (or similar) is found on SD card"
 
 config SPIFLASH
-	bool "Freescale PBL is found on SPI flash"
+	bool "Freescale PBL (or similar) is found on SPI flash"
+
+config NO_PBL
+	bool "Freescale PBL (or similar) is not used in this case"
 
 endchoice