Convert CONFIG_ARCH_MAP_SYSMEM to Kconfig

This converts the following to Kconfig:
   CONFIG_ARCH_MAP_SYSMEM

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/Kconfig b/arch/Kconfig
index ba2c57d..ee32e83 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -1,3 +1,7 @@
+config ARCH_MAP_SYSMEM
+	depends on SANDBOX || NDS32
+	def_bool y
+
 config CREATE_ARCH_SYMLINK
 	bool
 
diff --git a/arch/sandbox/Kconfig b/arch/sandbox/Kconfig
index 7cdbaef..477c519 100644
--- a/arch/sandbox/Kconfig
+++ b/arch/sandbox/Kconfig
@@ -1,9 +1,6 @@
 menu "Sandbox architecture"
 	depends on SANDBOX
 
-config ARCH_MAP_SYSMEM
-	def_bool y
-
 config SYS_ARCH
 	default "sandbox"