cros-ec-keyboard: Synchronize DT binding from linux

The ChromeOS EC keyboard is used by various different chromebooks. Peach
pi being the third board in the u-boot tree to use it (snow and peach
pit the other two). Rather then embedding the same big DT node in the
peach-pi DT again, copy the dtsi snippit & bindings documentation from
linux and include it in all 3 boards.

This slightly changes the dt bindings in u-boot:
  * google,key-rows becomes keypad,num-rows
  * google,key-colums becomes keypad,num-colums
  * google,repeat-delay-ms and google,repeat-rate-ms are no longer used
    and replaced by hardcoded values (similar to tegra kbc)

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/exynos5800-peach-pi.dts b/arch/arm/dts/exynos5800-peach-pi.dts
index 2f9d2db..e7c380f 100644
--- a/arch/arm/dts/exynos5800-peach-pi.dts
+++ b/arch/arm/dts/exynos5800-peach-pi.dts
@@ -96,7 +96,7 @@
 	spi@12d40000 { /* spi2 */
 		spi-max-frequency = <4000000>;
 		spi-deactivate-delay = <200>;
-		cros-ec@0 {
+		cros_ec: cros-ec@0 {
 			reg = <0>;
 			compatible = "google,cros-ec";
 			spi-half-duplex;
@@ -150,3 +150,5 @@
 		samsung,dual-lcd-enabled = <0>;
 	};
 };
+
+#include "cros-ec-keyboard.dtsi"