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/ventana_defconfig b/configs/ventana_defconfig
index 7439165..c33862c 100644
--- a/configs/ventana_defconfig
+++ b/configs/ventana_defconfig
@@ -5,6 +5,7 @@
 CONFIG_TEGRA20=y
 CONFIG_TARGET_VENTANA=y
 CONFIG_OF_SYSTEM_SETUP=y
+CONFIG_SPL_TEXT_BASE=0x00108000
 CONFIG_SYS_PROMPT="Tegra20 (Ventana) # "
 # CONFIG_CMD_IMI is not set
 # CONFIG_CMD_FLASH is not set