Convert CONFIG_SYS_MALLOC_LEN to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_MALLOC_LEN

Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/Kconfig b/Kconfig
index fb77b68..35d619f 100644
--- a/Kconfig
+++ b/Kconfig
@@ -249,8 +249,11 @@
 
 config SYS_MALLOC_LEN
 	hex "Define memory for Dynamic allocation"
-	depends on ARCH_ZYNQ || ARCH_VERSAL || ARCH_STM32MP || ARCH_ROCKCHIP
-	default 0x2000000 if ARCH_ROCKCHIP
+	default 0x2000000 if ARCH_ROCKCHIP || ARCH_OMAP2PLUS || ARCH_MESON
+	default 0x4020000 if ARCH_SUNXI && !MACH_SUN8I_V3S
+	default 0x200000 if ARCH_BMIPS || X86
+	default 0x220000 if ARCH_SUNXI && MACH_SUN8I_V3S
+	default 0x400000
 	help
 	  This defines memory to be allocated for Dynamic allocation
 	  TODO: Use for other architectures