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/pico-imx7d_defconfig b/configs/pico-imx7d_defconfig
index aa9172c..29b0745 100644
--- a/configs/pico-imx7d_defconfig
+++ b/configs/pico-imx7d_defconfig
@@ -17,6 +17,7 @@
 CONFIG_BOOTCOMMAND="run findfdt; run finduuid; run distro_bootcmd"
 CONFIG_DEFAULT_FDT_FILE="ask"
 CONFIG_BOUNCE_BUFFER=y
+CONFIG_SPL_TEXT_BASE=0x00911000
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_USB_HOST_SUPPORT=y
 CONFIG_SPL_USB_GADGET=y