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/am3517_crane_defconfig b/configs/am3517_crane_defconfig
index 8a72a04..07067a5 100644
--- a/configs/am3517_crane_defconfig
+++ b/configs/am3517_crane_defconfig
@@ -8,6 +8,7 @@
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_SPL=y
 CONFIG_BOOTDELAY=10
+CONFIG_SPL_TEXT_BASE=0x40200800
 # CONFIG_SPL_FS_EXT4 is not set
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMDLINE_EDITING is not set