boston: Remove unused label in lowlevel_display

The lowlevel_display() function includes a "1:" label which is never
used. Remove it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

board/imgtec/boston/lowlevel_init.S

@@ -51,5 +51,5 @@ LEAF(lowlevel_display)
 	sw	k1, 4(AT)
 #endif
 	.set	pop
-1:	jr	ra
+	jr	ra
 	END(lowlevel_display)