sunxi: Correct select's of SPL_STACK_R and SPL_SYS_MALLOC_SIMPLE

On ARCH_SUNXI we've been selecting these targets for a long time if
SUPPORT_SPL is set.  However, Lichee Pi Zero is the first platform we've
added that does support SPL but does not build SPL and has exposed a
latent bug.  Both of these symbols depend on SPL not SUPPORT_SPL, so we
need to update our select here otherwise we get a Kconfig warning.

Fixes: f02abb0608 ("sunxi: add support for Lichee Pi Zero")
Signed-off-by: Tom Rini <trini@konsulko.com>

arch/arm/Kconfig

@@ -666,8 +666,8 @@ config ARCH_SUNXI
 	select OF_BOARD_SETUP
 	select OF_CONTROL
 	select OF_SEPARATE
-	select SPL_STACK_R if SUPPORT_SPL
-	select SPL_SYS_MALLOC_SIMPLE if SUPPORT_SPL
+	select SPL_STACK_R if SPL
+	select SPL_SYS_MALLOC_SIMPLE if SPL
 	select SYS_NS16550
 	select SPL_SYS_THUMB_BUILD if !ARM64
 	select USB if DISTRO_DEFAULTS