ice: add support for 3k signing DDP sections for E825C

E825C devices shall support the new signing type of RSA 3K for new DDP
section (SEGMENT_SIGN_TYPE_RSA3K_E825 (5) - already in the code).
The driver is responsible to verify the presence of correct signing type.
Add 3k signinig support for E825C devices based on mac_type:
ICE_MAC_GENERIC_3K_E825;

Signed-off-by: Grzegorz Nitka <grzegorz.nitka@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>