sdhci: pci: Fix up power if device has ACPI companion

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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>