linux-phytec-ti

net: prueth: Add promiscuous mode support

Add support to enable/disable promiscuous mode.

There shouldn't be firmware compatibility breakage as
we're not using RELEASE version and HOST_Q1_RX_CONTEXT_OFFSET remains
unchanged while adding the PROMISCUOUS_MODE control.

Although Ethernet will work with existing firmware,
a firmware update is required for promiscuous mode to work.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>