mmc: add DT bindings for more MMC capability flags

Many MMC capability flags are platform-dependent and are traditionally set
in platform data. With DT often each such capability requires a special
binding. Add bindings for MMC_CAP_SD_HIGHSPEED, MMC_CAP_MMC_HIGHSPEED,
MMC_CAP_POWER_OFF_CARD and MMC_CAP_SDIO_IRQ capabilities. Also add code to
DT parser to look up "keep-power-in-suspend" and "enable-sdio-wakeup"
bindings and set MMC_PM_KEEP_POWER and MMC_PM_WAKE_SDIO_IRQ respectively,
if found.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index 654b705..85aada2 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -24,6 +24,10 @@
 - max-frequency: maximum operating clock frequency
 - no-1-8-v: when present, denotes that 1.8v card voltage is not supported on
   this system, even if the controller claims it is.
+- cap-sd-highspeed: SD high-speed timing is supported
+- cap-mmc-highspeed: MMC high-speed timing is supported
+- cap-power-off-card: powering off the card is safe
+- cap-sdio-irq: enable SDIO IRQ signalling on this interface
 
 *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line
 polarity properties, we have to fix the meaning of the "normal" and "inverted"