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/mccmon6_sd_defconfig b/configs/mccmon6_sd_defconfig
index 7a3a01a..aac433c 100644
--- a/configs/mccmon6_sd_defconfig
+++ b/configs/mccmon6_sd_defconfig
@@ -13,6 +13,7 @@
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/liebherr/mccmon6/mon6_imximage_sd.cfg"
 # CONFIG_USE_BOOTCOMMAND is not set
 CONFIG_BOUNCE_BUFFER=y
+CONFIG_SPL_TEXT_BASE=0x00908000
 CONFIG_SPL_BOARD_INIT=y
 CONFIG_SPL_ENV_SUPPORT=y
 CONFIG_SPL_NOR_SUPPORT=y