configs: chromebook snow: bump to linux 4.6.3

No significant changes but 4.6.3 moved parts of the device tree
into a different file, so dts patch must be updated.

[Peter: explicitly configure kernel headers for 4.6]
Signed-off-by: Alex Suykov <alex.suykov@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/chromebook/snow/linux-4.6-dts-tpm.patch

@@ -10,9 +10,9 @@ and https://lkml.org/lkml/2013/3/4/242
 
 Signed-off-by: Alex Suykov <alex.suykov@gmail.com>
 
---- a/arch/arm/boot/dts/exynos5250-snow.dts
-+++ b/arch/arm/boot/dts/exynos5250-snow.dts
-@@ -474,6 +474,11 @@
+--- a/arch/arm/boot/dts/exynos5250-snow-common.dtsi
++++ b/arch/arm/boot/dts/exynos5250-snow-common.dtsi
+@@ -466,6 +466,11 @@
  	status = "okay";
  	samsung,i2c-sda-delay = <100>;
  	samsung,i2c-max-bus-freq = <66000>;
@@ -24,3 +24,4 @@ Signed-off-by: Alex Suykov <alex.suykov@gmail.com>
  };
  
  &i2c_5 {
+