ti: remove usage of DM_I2C_COMPAT and don't disable DM_I2C in SPL

DM_I2C_COMPAT is a compatibility layer that allows using the non-DM I2C
API when DM_I2C is used. The goal is to eventually remove DM_I2C_COMPAT
when all I2C "clients" have been migrated to use the DM API.
This a step in that direction for the TI based platforms.
Build tested with buildman:
buildman -dle am33xx ti omap3 omap4 omap5 davinci keystone

boot tested with:
am335x_evm, am335x_boneblack, am335x_boneblack_vboot (DM version),
am57xx_evm, dra7xx_evm, k2g_evm, am437x_evm

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/board/ti/am335x/mux.c b/board/ti/am335x/mux.c
index 41333f9..04f4b8e 100644
--- a/board/ti/am335x/mux.c
+++ b/board/ti/am335x/mux.c
@@ -329,12 +329,23 @@
 {
 	unsigned short val;
 
+#ifndef CONFIG_DM_I2C
 	if (i2c_probe(I2C_CPLD_ADDR))
 		return PROFILE_NONE;
 
 	if (i2c_read(I2C_CPLD_ADDR, CFG_REG, 1, (unsigned char *)(&val), 2))
 		return PROFILE_NONE;
+#else
+	struct udevice *dev = NULL;
+	int rc;
 
+	rc = i2c_get_chip_for_busnum(0, I2C_CPLD_ADDR, 1, &dev);
+	if (rc)
+		return PROFILE_NONE;
+	rc = dm_i2c_read(dev, CFG_REG, (unsigned char *)(&val), 2);
+	if (rc)
+		return PROFILE_NONE;
+#endif
 	return (1 << (val & PROFILE_MASK));
 }