sunxi: Add DRAM_SUN4I kconfig entry

Add proper and simple kconfig option for dram_sun4i.c
instead of using MACH type on Makefile.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>

arch/arm/mach-sunxi/Kconfig

@@ -6,6 +6,12 @@ config SPL_LDSCRIPT
 config IDENT_STRING
 	default " Allwinner Technology"
 
+config DRAM_SUN4I
+	bool
+	help
+	  Select this dram controller driver for Sun4/5/7i platforms,
+	  like A10/A13/A20.
+
 config DRAM_SUN6I
 	bool
 	help
@@ -108,6 +114,7 @@ config MACH_SUN4I
 	bool "sun4i (Allwinner A10)"
 	select CPU_V7
 	select ARM_CORTEX_CPU_IS_UP
+	select DRAM_SUN4I
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
 
@@ -115,6 +122,7 @@ config MACH_SUN5I
 	bool "sun5i (Allwinner A13)"
 	select CPU_V7
 	select ARM_CORTEX_CPU_IS_UP
+	select DRAM_SUN4I
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
 	imply CONS_INDEX_2 if !DM_SERIAL
@@ -138,6 +146,7 @@ config MACH_SUN7I
 	select CPU_V7_HAS_NONSEC
 	select CPU_V7_HAS_VIRT
 	select ARCH_SUPPORT_PSCI
+	select DRAM_SUN4I
 	select SUNXI_GEN_SUN4I
 	select SUPPORT_SPL
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT

arch/arm/mach-sunxi/Makefile

@@ -33,10 +33,8 @@ endif
 obj-$(CONFIG_MACH_SUN9I)	+= clock_sun9i.o gtbus_sun9i.o
 
 ifdef CONFIG_SPL_BUILD
+obj-$(CONFIG_DRAM_SUN4I)	+= dram_sun4i.o
 obj-$(CONFIG_DRAM_SUN6I)	+= dram_sun6i.o
-obj-$(CONFIG_MACH_SUN4I)	+= dram_sun4i.o
-obj-$(CONFIG_MACH_SUN5I)	+= dram_sun4i.o
-obj-$(CONFIG_MACH_SUN7I)	+= dram_sun4i.o
 obj-$(CONFIG_MACH_SUN8I_A23)	+= dram_sun8i_a23.o
 obj-$(CONFIG_MACH_SUN8I_A33)	+= dram_sun8i_a33.o
 obj-$(CONFIG_MACH_SUN8I_A83T)	+= dram_sun8i_a83t.o