[media] cx23885: fix size helper functions

[media] cx23885: fix size helper functions

The norm_swidth function was unused and is dropped. It's not clear
what the purpose of that function was.

The norm_maxh function was changed so it tests for 60 Hz standards
rather than for 50 Hz standards. The is the preferred order.

The norm_maxw function was poorly written and used: it gives the maximum
allowed line width for the given standard. For 60 Hz that's 720, but
for 50 Hz that's 768 which allows for 768x576 which gives you square
pixels. For 60 Hz formats it is 640x480 that gives square pixels, so
there is no need to go beyond 720.

The initial width was set using norm_maxh(), which was wrong. Just set
to 720, that's what you normally use. Since the initial standard was
NTSC anyway the initial width was always 720 anyway.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>