spi: mt7621: fix missing clk_disable_unprepare() on error in mt7621_spi_probe

spi: mt7621: fix missing clk_disable_unprepare() on error in mt7621_spi_probe

[ Upstream commit 702b15cb97123cedcec56a39d9a21c5288eb9ae1 ]

Fix the missing clk_disable_unprepare() before return
from mt7621_spi_probe in the error handling case.

Fixes: cbd66c626e16 ("spi: mt7621: Move SPI driver out of staging")
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Link: https://lore.kernel.org/r/20201103074912.195576-1-miaoqinglang@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>