ASoC: jz4740-i2s: add missed checks for clk_get()

ASoC: jz4740-i2s: add missed checks for clk_get()

BugLink: https://bugs.launchpad.net/bugs/1910111
[ Upstream commit 1c1fb2653a0c2e3f310c07eacd8fc3a10e08c97a ]

jz4740_i2s_set_sysclk() does not check the return values of clk_get(),
while the file dereferences the pointers in clk_put().
Add the missed checks to fix it.

Fixes: 11bd3dd1b7c2 ("ASoC: Add JZ4740 ASoC support")
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Link: https://lore.kernel.org/r/20201203144227.418194-1-hslester96@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>