Fix up a power state in case PCI device has an ACPI companion.

Do it only for Intel Merrifield for now.

This is almost copy'n'paste of part of sdhci_acpi_probe() and might be
split out to a helper function in the future.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>