sunxi: Provide defaults for R40 DRAM settings

These values were taken from the Banana Pi M2 Ultra fex file
found in the released vendor BSP. This is the only publicly
available R40 device at the time of this writing.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>

board/sunxi/Kconfig

@@ -203,6 +203,7 @@ config DRAM_TYPE
 config DRAM_CLK
 	int "sunxi dram clock speed"
 	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 672 if MACH_SUN50I
@@ -224,6 +225,7 @@ 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 3881979 if MACH_SUN8I_R40
 	default 4145117 if MACH_SUN9I
 	default 3881915 if MACH_SUN50I
 	---help---
@@ -233,6 +235,7 @@ config DRAM_ODT_EN
 	bool "sunxi dram odt enable"
 	default n if !MACH_SUN8I_A23
 	default y if MACH_SUN8I_A23
+	default y if MACH_SUN8I_R40
 	default y if MACH_SUN50I
 	---help---
 	Select this to enable dram odt (on die termination).