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/cm_t54_defconfig b/configs/cm_t54_defconfig
index 05ac37c..fa9972b 100644
--- a/configs/cm_t54_defconfig
+++ b/configs/cm_t54_defconfig
@@ -11,6 +11,7 @@
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 # CONFIG_MISC_INIT_R is not set
 CONFIG_VERSION_VARIABLE=y
+CONFIG_SPL_TEXT_BASE=0x40300000
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR=0x200
 # CONFIG_SPL_NAND_SUPPORT is not set
 CONFIG_SPL_SATA_SUPPORT=y