e1000e: set fixed clock frequency indication for Nahum 11 and Nahum 13

[ Upstream commit 688a0d61 ]

On some systems with Nahum 11 and Nahum 13 the value of the XTAL clock in
the software STRAP is incorrect. This causes the PTP timer to run at the
wrong rate and can lead to synchronization issues.

The STRAP value is configured by the system firmware, and a firmware
update is not always possible. Since the XTAL clock on these systems
always runs at 38.4MHz, the driver may ignore the STRAP and just set
the correct value.

Fixes: cc23f4f0 ("e1000e: Add support for Meteor Lake")
Signed-off-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Tested-by: Mor Bar-Gabay <morx.bar.gabay@intel.com>
Reviewed-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>