mmc: sdhci-of-arasan: Add missed checks for devm_clk_register()

mmc: sdhci-of-arasan: Add missed checks for devm_clk_register()

These functions do not check the return value of devm_clk_register():
  - sdhci_arasan_register_sdcardclk()
  - sdhci_arasan_register_sampleclk()

Therefore, add the missed checks to fix them.

Fixes: c390f2110adf1 ("mmc: sdhci-of-arasan: Add ability to export card clock")
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200608162226.3259186-1-hslester96@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>