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/T1042D4RDB_NAND_defconfig b/configs/T1042D4RDB_NAND_defconfig
index 2cd3440..ed90250 100644
--- a/configs/T1042D4RDB_NAND_defconfig
+++ b/configs/T1042D4RDB_NAND_defconfig
@@ -11,7 +11,7 @@
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_OF_STDOUT_VIA_ALIAS=y
-CONFIG_SYS_EXTRA_OPTIONS="RAMBOOT_PBL,SPL_FSL_PBL"
+CONFIG_SYS_EXTRA_OPTIONS="RAMBOOT_PBL"
 CONFIG_BOOTDELAY=10
 CONFIG_SILENT_CONSOLE=y
 # CONFIG_CONSOLE_MUX is not set
@@ -19,6 +19,8 @@
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_BOARD_EARLY_INIT_R=y
 # CONFIG_SPL_FRAMEWORK is not set
+CONFIG_SPL_NAND_BOOT=y
+CONFIG_SPL_FSL_PBL=y
 CONFIG_SPL_TEXT_BASE=0xFFFD8000
 CONFIG_SPL_ENV_SUPPORT=y
 CONFIG_SPL_I2C_SUPPORT=y