Merge branch 'xgene_txrx_delay'

Iyappan Subramanian says:

====================
drivers: xgene: Add support RGMII TX/RX delay configuration

X-Gene RGMII ethernet controller has a RGMII bridge that performs the
task of converting the RGMII signal {RX_CLK,RX_CTL, RX_DATA[3:0]} from
PHY to GMII signal {RX_DV,RX_ER,RX_DATA[7:0]} and vice versa.  This
RGMII bridge has a provision to internally delay the input RX_CLK and
the output TX_CLK using configuration registers. This will help in
maintain the CLK-CTL delay relationship in various operating
conditions.

This patch adds support RGMII TX/RX delay configuration.
====================

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>