arm64: only select PINCTRL for Allwinner platforms

As the pinctrl driver selecting is refactored in Kconfig file of
pinctrl-sunxi, now we can select only PINCTRL for Allwinner platform,
and the default value of several pinctrl drivers useful on ARM64
Allwinner SoCs will become Y.

This is the situation of 32-bit ARM ARCH_SUNXI option.

Drop the select of per-SoC pinctrl choices, but keep selecting PINCTRL.
Signed-off-by: NIcenowy Zheng <icenowy@aosc.xyz>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

arch/arm64/Kconfig.platforms

@@ -4,7 +4,6 @@ config ARCH_SUNXI
 	bool "Allwinner sunxi 64-bit SoC Family"
 	select GENERIC_IRQ_CHIP
 	select PINCTRL
-	select PINCTRL_SUN50I_A64
 	help
 	  This enables support for Allwinner sunxi based SoCs like the A64.