sunxi: select SYS_NS16550 from Kconfig

Select SYS_NS16550 from Kconfig instead of setting it in all our
defconfig files.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index fb9176b..7383975 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -524,6 +524,7 @@
 	select OF_SEPARATE
 	select SPL_STACK_R if !MACH_SUN9I
 	select SPL_SYS_MALLOC_SIMPLE if !MACH_SUN9I
+	select SYS_NS16550
 	select USB
 	select USB_STORAGE
 	select USB_KEYBOARD