spca561:  Input buffer may be changed on reg write.
(all sd): Cleanup code, 'const' added.
Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

Done for conex, etoms, pac7311, sonixj, t613 and tv8532.
Code cleanup for some other subdrivers.
Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

- remaning subdrivers added
- remove the decoding helper and some specific frame decodings
Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>