sb/intel/i82371eb: Fix iasl warning

The backslash on the very last line is not needed and causes an iasl
warning.

Change-Id: I27e78bc34b9386dd014db5880a104693b4f0db5a
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41094
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/southbridge/intel/i82371eb/acpi/intx.asl

@@ -45,4 +45,4 @@ Device(intx) {						\
 		}					\
 		Store(Local0, pinx)			\
 	}						\
-}							\
+}