i2c: meson: fix missing clk_disable_unprepare() on error in meson_i2c_probe()

Fix the missing clk_disable_unprepare() before return
from meson_i2c_probe() in the error handling case.

Fixes: a57f9b4d

 ("i2c: meson: Use 50% duty cycle for I2C clock")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>