Input: iqs5xx - remove superfluous revision validation

Input: iqs5xx - remove superfluous revision validation

The vendor-assigned firmware project number is restricted to the
generic project number (15); however the vendor may assign other
project numbers to specific applications and customers.

These custom project numbers may be based on forwards-compatible
firmware revision 1.x. However, the driver unnecessarily rejects
anything older than firmware revision 2.0.

To support other applications, remove these unnecessarily strict
checks and enter the bootloader only for truly incompatible A000
devices.

Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Link: https://lore.kernel.org/r/20210313191236.4366-5-jeff@labundy.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>