Merge branch 'xgene-check-all-RGMII-phy-mode-variants'

Iyappan Subramanian says:

====================
Check all RGMII phy mode variants

This patch set,
     - adds phy_interface_mode_is_rgmii() helper function
     - addresses review comment from previous patch set, by calling
       phy_interface_mode_is_rgmii() to address all RGMII variants

v2: Address review comments from v1
     - adds phy_interface_mode_is_rgmii() helper function
     - addresses review comment from previous patch set, by calling
       phy_interface_mode_is_rgmii() to address all RGMII variants
v1:
     - Initial version
====================

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