net: phy: genphy: Allow overwriting features

net: phy: genphy: Allow overwriting features

of_set_phy_supported allows overwiting hardware capabilities of
a phy with values from the devicetree. This does not work with
the genphy driver though because the genphys config_init function
will overwrite all values adjusted by of_set_phy_supported. Fix
this by initialising the genphy features in the phy_driver struct
and in config_init just limit the features to the ones the hardware
can actually support. The resulting features are a subset of the
devicetree specified features and the hardware features.

This is a copy of the patch from Linux kernel, see
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c242a47238fa2a6a54af8a16e62b54e6e031d4bc

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>