em(4) Rx and Tx descriptors

[Matthew Dillon]

:I have no objection to add two read only sysctl nodes; It may be
:better than parsing dmesg if certain program needs those values.  If
:Matt thinks it is OK too, I will commit it.
:
:Best Regards,
:sephe

    I think its probably a bit bloated, but even so it IS a reasonable
    solution and we need to move on, so please go ahead and commit it.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>