spl: Kconfig: ARCH_K3: Set default SPL_STACK_R_MALLOC_SIMPLE_LEN for R5 build

All ARCH_K3 platforms need about of 2MB of malloc space post
reallocation. Since, this space is allocated from SDRAM, provide a
generous 2MB space by default.

Platforms requiring more than 2MB can override in defconfig as needed.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 6405374..46bacad 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -409,6 +409,7 @@
 	depends on SPL_STACK_R && SPL_SYS_MALLOC_SIMPLE
 	hex "Size of malloc_simple heap after switching to DRAM SPL stack"
 	default 0x400000 if ARCH_K3 && ARM64
+	default 0x200000 if ARCH_K3 && CPU_V7R
 	default 0x100000
 	help
 	  Specify the amount of the stack to use as memory pool for