mainboard/google/kahlee: Add EC back into grunt devicetree

The EC code should not have been removed from devicetree when moving
over from grunt.  This was causing various bewildering issues that
would happen on the first boot but not on subsequent reboots.

BUG=b:73235377
TEST=Grunt powers off and stays powered off at dev screen.

Change-Id: I225138fede66c6e189e0e79d1261d0d579f7cbdc
Signed-off-by: Martin Roth <martinroth@chromium.org>
Reviewed-on: https://review.coreboot.org/25690
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Marc Jones <marc@marcjonesconsulting.com>

src/mainboard/google/kahlee/variants/grunt/devicetree.cb

@@ -73,6 +73,9 @@ chip soc/amd/stoneyridge
 		device pci 14.0 on      # SMbus
 		end # SMbus
 		device pci 14.3 on
+			chip ec/google/chromeec
+				device pnp 0c09.0 on end
+			end
 		end # LPC
 		device pci 14.7 on  end # SD
 		device pci 18.0 on  end