[media] radio-aztech: Convert to generic lm7000 implementation

Aztech radio card is based on LM7001 chip which is (software) compatible with LM7000.
So remove the LM7000-specific code from the driver and use generic code.
Also found that the card does not have A0..A2 ISA pins connected, which means that the region size is 8 bytes.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>