Input: atmel_mxt_ts - add additional bootloader addresses

Move bootloaders reads/writes into separate functions. Instead of switching
client->addr, define new field bootloader_addr in mxt_data. Implement
lookup calculation for bootloader addresses.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
Acked-by: Benson Leung <bleung@chromium.org>
Acked-by: Yufeng Shen <miletus@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>