[media] exynos4-is: Cleanup a define in mipi-csis driver

This define is only used in s5pcsis_irq_handler():
	if ((status & S5PCSIS_INTSRC_NON_IMAGE_DATA) && pktbuf->data) {
The problem is that "status" is a 32 bit and (0xff << 28) is larger than
32 bits and that sets off a static checker warning.  I consulted with
Sylwester Nawrocki and the define should actually be (0xf << 28).

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>