The zr36067 driver doesn't make a distinction between the different sub-types
of NTSC, PAL, or SECAM norms.  For example, when the enum std ioctl returns
the PAL standard it returns PAL_BG|PAL_DK|PAL_H|PAL_I.

When setting the norm, it required the bitmask to match exactly the set of
norms used during the enumeration.  If just one norm was specified, for
example PAL_BG or NTSC_M, it would fail.  This violates the V4L2 spec,
"VIDIOC_S_STD accepts *one* or more flags..."

The key thing to realize is that V4L2_STD_PAL is not one bit, it is multiple
bits.  It's ok to call S_STD with any *one* of those bits, but the driver was
requiring *all* of them.

This fixes the S_STD function so that it will accept any set of one or more
PAL norms as PAL, and the same for NTSC and SECAM.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Acked-by: Ronald S. Bultje <rbultje@ronald.bitfreak.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>