net/ice/base: add macro specifying max NVM offset

net/ice/base: add macro specifying max NVM offset

The ice_aq_read_nvm function uses a somewhat weird construction for
verifying that the incoming offset is valid. Replace this construction
with a simple greater-than expression, and define the maximum value
(24bits) in the ice_adminq_cmd.h

By providing a macro, the check becomes more clear. Additionally the
maximum offset can be used in other locations.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Qiming Yang <qiming.yang@intel.com>