mmc: sdhci-acpi: add probe_slot method for emmc/sd/sdio

Similar to sdhci-pci controller, also add probe_slot
and remove_slot method in the sdhci-acpi driver.

Signed-off-by: Yunpeng Gao <yunpeng.gao@intel.com>
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>