configs: Migrate the various SPL_BOOT_xxx choices for PowerPC

The non-CONFIG_SPL_FRAMEWORK SPL used on some PowerPC platforms have a
choice between CONFIG_SPL_NAND_BOOT, CONFIG_SPL_MMC_BOOT and
CONFIG_SPL_SPI_BOOT.  Migrate this to Kconfig

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ls1021aqds_sdcard_ifc_defconfig b/configs/ls1021aqds_sdcard_ifc_defconfig
index c85c831..daabf76 100644
--- a/configs/ls1021aqds_sdcard_ifc_defconfig
+++ b/configs/ls1021aqds_sdcard_ifc_defconfig
@@ -11,7 +11,7 @@
 CONFIG_AHCI=y
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
-CONFIG_SYS_EXTRA_OPTIONS="RAMBOOT_PBL,SPL_FSL_PBL,SD_BOOT"
+CONFIG_SYS_EXTRA_OPTIONS="RAMBOOT_PBL,SD_BOOT"
 CONFIG_SD_BOOT=y
 CONFIG_BOOTDELAY=3
 CONFIG_SILENT_CONSOLE=y