drivers/intel/gma/acpi: Replace Increment() with ASL 2.0 syntax

Replace `Increment(a)` with `a++`.

Change-Id: If0c11f43713bf7afec6dd600289776eefd1331e8
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60580
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
diff --git a/src/drivers/intel/gma/acpi/configure_brightness_levels.asl b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
index f0e6c31..99d2bc5 100644
--- a/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
+++ b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
@@ -134,7 +134,7 @@
 					}
 				}
 
-				Increment (Local1)
+				Local1++
 			}
 
 			/* Didn't find greater/equal value: use the last */