ec/hp/kbc1126/acpi: Replace Add(a,b,c) with ASL 2.0 syntax

Replace `Add (a, b, c)` with `c = a + b`.

Change-Id: I48d471730d36200f5496effaad00a06222be85d9
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60485
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

src/ec/hp/kbc1126/acpi/battery.asl

@@ -230,7 +230,7 @@ Method (\ISTR, 2, Serialized)
 	{
 		Local1--
 		Divide (Local0, 10, Local2, Local0)
-		Add (Local2, 48, NUMB[Local1])
+		NUMB[Local1] = Local2 + 48
 	}
 	ToString (NUMB, Arg1, Local3)
 	Return (Local3)