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/configs/P2020RDB-PC_36BIT_defconfig b/configs/P2020RDB-PC_36BIT_defconfig
index b1dbca6..1640f23 100644
--- a/configs/P2020RDB-PC_36BIT_defconfig
+++ b/configs/P2020RDB-PC_36BIT_defconfig
@@ -21,7 +21,7 @@
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_OF_STDOUT_VIA_ALIAS=y
-CONFIG_FSL_FIXED_MMC_LOCATION=y
+CONFIG_NO_PBL=y
 CONFIG_BOOTDELAY=10
 CONFIG_USE_BOOTCOMMAND=y
 CONFIG_BOOTCOMMAND="setenv bootargs root=/dev/$bdev rw rootdelay=30 console=$consoledev,$baudrate $othbootargs;usb start;ext2load usb 0:1 $loadaddr /boot/$bootfile;ext2load usb 0:1 $fdtaddr /boot/$fdtfile;bootm $loadaddr - $fdtaddr"