ARM: sunxi: Select HAVE_ARM_ARCH_TIMER

In order for the architected timers support to be enabled in the kernel, this
option has to be enabled. Otherwise, the architected timers driver won't be
compiled in, and we will not get to use them.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>