sunxi: enable DRAM initialization and SPL for V3s SoC

As we have already support for the DesignWare DRAM controller and the
integrated DDR2 chip of V3s, let's enable the SPL support for V3s.

This patch also contains the default DRAM configuration for V3s.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com>

arch/arm/mach-sunxi/Kconfig

@@ -151,6 +151,9 @@ config MACH_SUN8I_V3S
 	select CPU_V7_HAS_VIRT
 	select ARCH_SUPPORT_PSCI
 	select SUNXI_GEN_SUN6I
+	select SUNXI_DRAM_DW
+	select SUNXI_DRAM_DW_16BIT
+	select SUPPORT_SPL
 	select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
 
 config MACH_SUN9I
@@ -259,7 +262,8 @@ config DRAM_CLK
 	default 792 if MACH_SUN9I
 	default 648 if MACH_SUN8I_R40
 	default 312 if MACH_SUN6I || MACH_SUN8I
-	default 360 if MACH_SUN4I || MACH_SUN5I || MACH_SUN7I
+	default 360 if MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || \
+		       MACH_SUN8I_V3S
 	default 672 if MACH_SUN50I
 	---help---
 	Set the dram clock speed, valid range 240 - 480 (prior to sun9i),
@@ -279,6 +283,7 @@ config DRAM_ZQ
 	int "sunxi dram zq value"
 	default 123 if MACH_SUN4I || MACH_SUN5I || MACH_SUN6I || MACH_SUN8I
 	default 127 if MACH_SUN7I
+	default 14779 if MACH_SUN8I_V3S
 	default 3881979 if MACH_SUN8I_R40
 	default 4145117 if MACH_SUN9I
 	default 3881915 if MACH_SUN50I