V4L/DVB (7749): cx88: fix tuner setup

Tuner setup were happening during i2c attach callback. This means that it would
happen on two conditions:

	1) if tuner module weren't load, it will happen at request_module("tuner");

	2) if tuner is not compiled as a module, or it is already loaded
	   (for example, on setups with more than one tuner), it will happen
	   when cx88 registers I2C bus.

Due to that, if tuner were loaded, tuner setup will happen _before_ reading
the proper values at tuner eeprom. Since set_addr refuses to change for a tuner
that were previously defined (except if the tuner_addr is set), this were making
eeprom tuner detection useless.

This patch removes tuner type setup from cx88-i2c, moving it to the proper
place, after taking eeprom into account.

Reviewed-by: Gert Vervoort <gert.vervoort@hccnet.nl>
Reviewed-by: Ian Pickworth <ian@pickworth.me.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>