ARM: DRA74-evm: Use SMA_1 spare register to workaround DP83865 phy on SR2.0

ARM: DRA74-evm: Use SMA_1 spare register to workaround DP83865 phy on SR2.0

DP83865 ethernet phy used on DRA74x-evm is quirky and the datasheet
provided IODELAY values for standard RGMII phys do not work.

Silicon Revision(SR) 2.0 provides an alternative bit configuration
that allows us to do a "gross adjustment" to launch the data off a
different internal clock edge. Manual IO Delay overrides are still
necessary to fine tune the clock-to-data delays. This is a necessary
workaround for the quirky ethernet Phy we have on the platform.

NOTE: SMA registers are spare "kitchen sink" registers that does
contain bits for other workaround as necessary as well. Hence the
control for the same is introduced in a generic SoC specific, board
generic location.

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>