Merge branch 'Sub-ns-increment-fixes-in-Macb-PTP'

Harini Katakam says:

====================
Sub ns increment fixes in Macb PTP

The subns increment register fields are not captured correctly in the
driver. Fix the same and also increase the subns incr resolution.

Sub ns resolution was increased to 24 bits in r1p06f2 version. To my
knowledge, this PTP driver, with its current BD time stamp
implementation, is only useful to that version or above. So, I have
increased the resolution unconditionally. Please let me know if there
is any IP versions incompatible with this - there is no register to
obtain this information from.

Changes from RFC:
None
====================

Signed-off-by: David S. Miller <davem@davemloft.net>