V4L/DVB (10561): bttv: store card database more efficiently

The bttv card database is quite large and the data structure used to store
it wasn't very efficient.  Most of the field are only used at card
initialization time so it doesn't matter if they aren't efficient to
access.

Overall the changes reduce code size by 60 bytes in ia32.  The data size is
decreased by 5024 byes.  It is probably even more for 64-bit kernels.

Move the fields in the struct around to be sorted from largest to smallest.
This saves on padding space used for alignment.

Get rid of the unused digital_mode field.  Leave the setting as a comment
in the few cards entries that set it, in case someone ever writes the code.

Get rid of the unused audio_inputs field.  Leave the values in the card
entries in case someone ever writes code that might use it.

Get ride of the unused radio_addr field.  No card entries even set it to
anything interesting so it's not left as comments.  All the code that used
it was removed in commit v2.6.14-3466-g291d1d7 from Nov 8th 2005.

Reduce video_inputs to u8 as no card has more than 255 inputs (the most is
16).

Change tuner_addr to u8.  I2C addresses are only seven bits and 255 means
ADDR_UNSET, so everything fits.

Make has_radio a one bit flag.

Make the pll setting a two bit field.

Reduce svhs to four bits as no card has an s-video input above 9.  Change
the value for no s-video input from UNSET (which is -1U and out of range of
four bits) to NO_SVHS (which is now 15).

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>