sunxi: Revert "sunxi: make SoC variant choice mandatory"
This reverts commit 1a5f0de0 ("sunxi: make SoC variant choice mandatory"). With the optional marking in the Kconfig "make savedefconfig" will drop CONFIG_MACH_SUN4I=y from all the A10 boards, making it hard to see at a glance which family of sunxi chips the defconfig is for. This commit therefore restores the optional, and restores CONFIG_MACH_SUN4I=y to all defconfig's which had it dropped because of this. Signed-off-by: Hans de Goede <firstname.lastname@example.org> Acked-by: Ian Campbell <email@example.com>