omap3: Define common init stack pointer address in Kconfig

The init stack pointer was defined to the same value in each OMAP3
board defconfig. Move the common definition to the Kconfig option
declaration instead.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@konsulko.com>
Tested-by: Derald D. Woods <woods.technical@gmail.com>
diff --git a/Kconfig b/Kconfig
index 82df59f..98175a8 100644
--- a/Kconfig
+++ b/Kconfig
@@ -236,6 +236,7 @@
 config HAS_CUSTOM_SYS_INIT_SP_ADDR
 	bool "Use a custom location for the initial stack pointer address"
 	depends on ARC || (ARM && !INIT_SP_RELATIVE) || MIPS || PPC || RISCV
+	default y if OMAP34XX
 	default y if TFABOOT
 	help
 	  Typically, we use an initial stack pointer address that is calculated
@@ -249,6 +250,7 @@
 config CUSTOM_SYS_INIT_SP_ADDR
 	hex "Static location for the initial stack pointer"
 	depends on HAS_CUSTOM_SYS_INIT_SP_ADDR
+	default 0x4020ff00 if OMAP34XX
 	default TEXT_BASE if TFABOOT
 
 config SYS_MALLOC_F