clk: sunxi-ng: fix not NULL terminated coccicheck error

Fix the following coccicheck error:
./drivers/clk/sunxi-ng/ccu-sun6i-rtc.c:348:1-2: sun6i_rtc_ccu_match is
not NULL terminated at line 348

Fixes: d91612d7

 ("clk: sunxi-ng: Add support for the sun6i RTC clocks")
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220328073931.36544-1-wanjiabing@vivo.com