sunxi: Add DRAM_SUN8I_A23 kconfig entry

Add proper and simple kconfig option for dram_sun8i_a23.c
instead of using MACH type on Makefile.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index b4684de..5e4f616 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -18,6 +18,12 @@
 	  Select this dram controller driver for Sun6i platforms,
 	  like A31/A31s.
 
+config DRAM_SUN8I_A23
+	bool
+	help
+	  Select this dram controller driver for Sun8i platforms,
+	  for A23 SOC.
+
 config DRAM_SUN9I
 	bool
 	help
@@ -163,6 +169,7 @@
 	select CPU_V7_HAS_NONSEC
 	select CPU_V7_HAS_VIRT
 	select ARCH_SUPPORT_PSCI
+	select DRAM_SUN8I_A23
 	select SUNXI_GEN_SUN6I
 	select SUPPORT_SPL
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT