mmc: sdhci-milbeaut: Remove redundant platform_get_irq error message

platform_get_irq() will call dev_err() itself on failure,
so there is no need for the driver to also do this.
This is detected by coccinelle.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200116144322.57308-1-yuehaibing@huawei.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>