[media] v4l: vsp1: Fix VI6_WPF_SZCLIP_SIZE_MASK macro

Clipping size bit of VI6_WPFn _HSZCLIP and VI6_WPFn _VSZCLIP register are from
0 bit to 11 bit. But VI6_WPF_SZCLIP_SIZE_MASK is set to 0x1FFF, this will mask
until the reserve bits. This fixes size for VI6_WPF_SZCLIP_SIZE_MASK.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>