memory: exynos5422-dmc: handle clock enable failures

Check the return values of clk_prepare_enable() for fout_bpll and
mout_bpll.

If enabling fout_bpll fails, propagate the error. If enabling mout_bpll
fails, disable fout_bpll before returning. This keeps the clock enable
count balanced on probe error paths.

Fixes: 6e7674c3c6df ("memory: Add DMC driver for Exynos5422")
Signed-off-by: Jiawen Liu <1298662399@qq.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/tencent_B0189529F550458590E3BA614EAB800FBF08@qq.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>