msk(4): Align RX buffer on 8bytes for hardware w/ ram buffer

msk(4): Align RX buffer on 8bytes for hardware w/ ram buffer

Add another hardware bug workaround for Yukon II controllers that
have hardware ram buffer. The silicon bug seem to be triggered by
pause frames if receive buffer is not aligned on FIFO word(8 bytes).
To workaround the issue, make sure to align Rx buffers on 8 bytes.
Unfortunately this workaround requires yet another Rx fixup for
strict alignment architecture machines to align IP header.

For newer hardwares that lacks ram buffer may not have this bug so
check number of available ram buffer size to see the existence of
ram buffer.

Obtained-frim: FreeBSD 183346