ACPI: Add support for exposing BGRT data

ACPI 5.0 adds the BGRT, a table that contains a pointer to the firmware
boot splash and associated metadata. This simple driver exposes it via
/sys/firmware/acpi in order to allow bootsplash applications to draw their
splash around the firmware image and reduce the number of jarring graphical
transitions during boot.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 7556913..47768ff 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -384,6 +384,15 @@
 	  load additional kernel modules after boot, this feature may be used
 	  to override that restriction).
 
+config ACPI_BGRT
+        tristate "Boottime Graphics Resource Table support"
+        default n
+        help
+	  This driver adds support for exposing the ACPI Boottime Graphics
+	  Resource Table, which allows the operating system to obtain
+	  data from the firmware boot splash. It will appear under
+	  /sys/firmware/acpi/bgrt/ .
+
 source "drivers/acpi/apei/Kconfig"
 
 endif	# ACPI