Convert CONFIG_SPL_INIT_MINIMAL et al to Kconfig

This converts the following to Kconfig:
   CONFIG_SPL_INIT_MINIMAL
   CONFIG_SPL_FLUSH_IMAGE
   CONFIG_SPL_SKIP_RELOCATE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/T2080QDS_NAND_defconfig b/configs/T2080QDS_NAND_defconfig
index ec54a71..5b17526 100644
--- a/configs/T2080QDS_NAND_defconfig
+++ b/configs/T2080QDS_NAND_defconfig
@@ -35,6 +35,8 @@
 # CONFIG_SPL_FRAMEWORK is not set
 CONFIG_SPL_NAND_BOOT=y
 CONFIG_SPL_FSL_PBL=y
+CONFIG_SPL_FLUSH_IMAGE=y
+CONFIG_SPL_SKIP_RELOCATE=y
 CONFIG_SPL_ENV_SUPPORT=y
 CONFIG_SPL_I2C=y
 CONFIG_SPL_MPC8XXX_INIT_DDR=y