mmc: sdhci-acpi: add SDHCI ACPI driver

Add a driver for SDHCI controllers enumerated via ACPI and identified
by the ACPI Compatibility ID PNP0D40 (or other SDHCI-specific ACPI
hardware IDs in the future).

[rjw: Added the changelog.]
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Chris Ball <cjb@laptop.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 17ad0a7..0e4960a 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -9,6 +9,7 @@
 obj-$(CONFIG_MMC_SDHCI)		+= sdhci.o
 obj-$(CONFIG_MMC_SDHCI_PCI)	+= sdhci-pci.o
 obj-$(subst m,y,$(CONFIG_MMC_SDHCI_PCI))	+= sdhci-pci-data.o
+obj-$(CONFIG_MMC_SDHCI_ACPI)	+= sdhci-acpi.o
 obj-$(CONFIG_MMC_SDHCI_PXAV3)	+= sdhci-pxav3.o
 obj-$(CONFIG_MMC_SDHCI_PXAV2)	+= sdhci-pxav2.o
 obj-$(CONFIG_MMC_SDHCI_S3C)	+= sdhci-s3c.o