clk: meson: gxbb: fix build error without RESET_CONTROLLER

With CONFIG_RESET_CONTROLLER=n we see the following link error in the
meson gxbb clk driver:

drivers/built-in.o: In function 'gxbb_aoclkc_probe':
drivers/clk/meson/gxbb-aoclk.c:161: undefined reference to 'devm_reset_controller_register'

Fix this by selecting the reset controller subsystem.

Fixes: f8c11f79 ("clk: meson: Add GXBB AO Clock and Reset controller driver")
Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
[narmstrong: Added fixes-by tag]
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>