Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Correct broadcast frame handling. Setting bit6 of MCR0 register
enables broadcast filtering. Make sure to clear the bit to receive
broadcast frames. While I'm here rename the bit definition to
reflect reality.

Reported by: brad@OpenBSD
MFC after: 1 week

Add driver for DM&P Vortex86 RDC R6040 Fast Ethernet.
The controller is commonly found on DM&P Vortex86 x86 SoC. The
driver supports all hardware features except flow control. The
flow control was intentionally disabled due to silicon bug.

DM&P Electronics, Inc. provided all necessary information including
sample board to write driver and answered many questions I had.
Many thanks for their support of FreeBSD.

H/W donated by: DM&P Electronics, Inc.