clk: meson: Fix invalid use of sizeof in gxbb_aoclkc_probe()

sizeof() when applied to a pointer typed expression gives the
size of the pointer, not that of the pointed data.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Fixes: f8c11f79 ("clk: meson: Add GXBB AO Clock and Reset controller driver")
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>