mb/ocp/tiogapass: Convert to ASL 2.0 syntax

Generated build/dsdt.dsl files are identical.

Change-Id: Iffd6954dcb3f9fb8bcd89854d84f6944cb520dd1
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46208
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/ocp/tiogapass/acpi/platform.asl

@@ -329,8 +329,8 @@ Field (PSYS, ByteAcc, NoLock, Preserve)
 /* SMI I/O Trap */
 Method (TRAP, 1, Serialized)
 {
-	Store (Arg0, SMIF)	// SMI Function
-	Store (0, TRP0)		// Generate trap
+	SMIF = Arg0	// SMI Function
+	TRP0 = 0	// Generate trap
 	Return (SMIF)	// Return value of SMI handler
 }
 
@@ -345,7 +345,7 @@ Method (TRAP, 1, Serialized)
 Method (_PIC, 1)
 {
 	/* Remember the OS' IRQ routing choice. */
-	Store (Arg0, PICM)
+	PICM = Arg0
 }
 
 /*