mb/google/dedede/var/magolor: Enable EC keyboard backlight

BUG=b:177288782
TEST=emerge-dedede coreboot chromeos-bootimage

Change-Id: I98f741da4a22494883939c4efe7960c66e71c6a7
Signed-off-by: Tim Chen <tim-chen@quanta.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49340
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Henry Sun <henrysun@google.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

src/mainboard/google/dedede/variants/magolor/include/variant/ec.h

@@ -5,4 +5,7 @@
 
 #include <baseboard/ec.h>
 
+/* Enable Keyboard Backlight in ACPI */
+#define EC_ENABLE_KEYBOARD_BACKLIGHT
+
 #endif