[media] cx88: fix register mask

Ensure that the register is aligned to a dword, otherwise the read could
read out-of-range data.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/pci/cx88/cx88-video.c

@@ -1360,7 +1360,7 @@ static int vidioc_g_register (struct file *file, void *fh,
 	struct cx88_core *core = ((struct cx8800_fh*)fh)->dev->core;
 
 	/* cx2388x has a 24-bit register space */
-	reg->val = cx_read(reg->reg & 0xffffff);
+	reg->val = cx_read(reg->reg & 0xfffffc);
 	reg->size = 4;
 	return 0;
 }
@@ -1370,7 +1370,7 @@ static int vidioc_s_register (struct file *file, void *fh,
 {
 	struct cx88_core *core = ((struct cx8800_fh*)fh)->dev->core;
 
-	cx_write(reg->reg & 0xffffff, reg->val);
+	cx_write(reg->reg & 0xfffffc, reg->val);
 	return 0;
 }
 #endif