ec/google/chromeec/acpi: Replace Multiply(a,b,c) with ASL 2.0 syntax

Replace `Multiply (a, b, c)` with `c = a * b`.

Change-Id: Iea86e77df6c76756ed336f57a906ac0757aef1cf
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60647
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/ec/google/chromeec/acpi/ec.asl

@@ -201,7 +201,7 @@ Device (EC0)
 		Local0 += \_SB.PCI0.LPCB.EC0.TOFS
 
 		/* Convert to 1/10 Kelvin */
-		Multiply (Local0, 10, Local0)
+		Local0 *= 10
 
 		Return (Local0)
 	}