clk: sunxi-ng: fix build error without CONFIG_RESET_CONTROLLER

With CONFIG_RESET_CONTROLLER=n we get the following link error in the
sunxi-ng clk driver:

drivers/built-in.o: In function `sunxi_ccu_probe':
mux-core.c:(.text+0x12fe68): undefined reference to 'reset_controller_register'
mux-core.c:(.text+0x12fe68): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol 'reset_controller_register'

Fix this by adding the appropriate select statement.

Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>