e1000e: PTP lock in e1000e_phc_adjustfreq
e1000e: PTP lock in e1000e_phc_adjustfreq

Add lock in e1000e_phc_adjfreq to prevent concurrent changes to TIMINCA
and SYSTIMH/L.

Signed-off-by: Todd Fujinaka <466a62000b5b4767fc2c795fe80d3a0328f10ed6@intel.com>
Tested-by: Jeff Pieper <89ae28dca346dcf475c1c4c5ccad0a12c81be577@intel.com>
Signed-off-by: Jeff Kirsher <87e35f5be20bb3e67f4ba6b86f5f6be3085b1b3a@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs