Support for m88rs2000 chip used in lmedm04 driver.

Note there are still lock problems.

Slow channel change due to the large block of registers sent in set_frontend.

Version 2 differences.
Front end is completely shut down when in sleep mode. This allow user to regain
control of device.
Kaffeine scan problem solved by removing register calls from get_frontend.
Kaffeine seems to call get_frontend when updating signal data. This can happen
in the middle of a tune stalling the driver.
Change calculations to those in the DS3000 driver.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>