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/imx6dl_mamoj_defconfig b/configs/imx6dl_mamoj_defconfig
index 10e271c..6e668c5 100644
--- a/configs/imx6dl_mamoj_defconfig
+++ b/configs/imx6dl_mamoj_defconfig
@@ -10,6 +10,7 @@
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/mach-imx/spl_sd.cfg"
 CONFIG_BOOTDELAY=3
 CONFIG_BOUNCE_BUFFER=y
+CONFIG_SPL_TEXT_BASE=0x00908000
 CONFIG_SPL_OS_BOOT=y
 CONFIG_CRC32_VERIFY=y
 CONFIG_CMD_MEMTEST=y