configs: move CONFIG_SPL_TEXT_BASE to Kconfig

Moved CONFIG_SPL_TEXT_BASE to common/spl/Kconfig and migrate existing
values.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
[trini: Re-run migration]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/BSC9131RDB_NAND_defconfig b/configs/BSC9131RDB_NAND_defconfig
index e26ad53..13ad551 100644
--- a/configs/BSC9131RDB_NAND_defconfig
+++ b/configs/BSC9131RDB_NAND_defconfig
@@ -12,6 +12,7 @@
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 # CONFIG_MISC_INIT_R is not set
 # CONFIG_SPL_FRAMEWORK is not set
+CONFIG_SPL_TEXT_BASE=0xFFFFE000
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMD_FLASH is not set