sunxi: SPL SPI: Add SPI boot support for the Allwinner H616 SoC

The H616 SoC uses the same SPI IP as the H6, also shares the same clocks
and reset bits.
The only real difference is a slight change in the pin assignment: the
H6 uses PC5, the H616 PC4 instead. This makes for a small change in
our spi0_pinmux_setup() routine.

Apart from that, just extend the H6 #ifdef guards to also cover the H616,
using the shared CONFIG_SUN50I_GEN_H6 symbol.
Also use this symbol for the Kconfig dependency.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Ivan Shishkin <s45rus@gmail.com>
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 5712576..6b16f43 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -998,7 +998,7 @@
 
 config SPL_SPI_SUNXI
 	bool "Support for SPI Flash on Allwinner SoCs in SPL"
-	depends on MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || MACH_SUNXI_H3_H5 || MACH_SUN50I || MACH_SUN8I_R40 || MACH_SUN50I_H6 || MACH_SUNIV
+	depends on MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || MACH_SUNXI_H3_H5 || MACH_SUN50I || MACH_SUN8I_R40 || SUN50I_GEN_H6 || MACH_SUNIV
 	help
 	  Enable support for SPI Flash. This option allows SPL to read from
 	  sunxi SPI Flash. It uses the same method as the boot ROM, so does