phy: rockchip-emmc: emmc_phy_init() always return 0

stable inclusion
from stable-5.10.20
commit 95fdc1ea3bfc52f04508b5d7f0cf307604b3bcf9
bugzilla: 50608

--------------------------------

[ Upstream commit 39961bd6 ]

rockchip_emmc_phy_init() return variable is not set with the error value
if clk_get() failed. 'emmcclk' is optional, thus use clk_get_optional()
and if the return value != NULL make error processing and set the
return code accordingly.

Fixes: 52c0624a phy: rockchip-emmc: Set phyctrl_frqsel based on card clock
Signed-off-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20201210080454.17379-1-chris.ruehl@gtsys.com.hk


Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>