[media] staging: as102: Eliminate as10x_handle_t alias

Remove pre-processor defined as10x_handle_t data type by directly
replacing it with struct as102_bus_adapter_t. phandle is renamed
to adap inside function bodies.

Cc: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Sylwester Nawrocki <snjw23@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>