net: fsl_enetc: Enable optional ENETREF clock on i.MX95

net: fsl_enetc: Enable optional ENETREF clock on i.MX95

The ENETCv4 port DT nodes on i.MX95 may contain optional clock phandle
to IMX95_CLK_ENETREF "ref" clock. These "ref" clock must be enabled for
the ethernet to work. These "ref" clock are enabled after cold boot, but
when the system booted Linux and rebooted, those "ref" clock might have
been disabled in the process, which would make ethernet inoperable after
reboot. Make sure those "ref" clock are always correctly enabled.

Signed-off-by: Marek Vasut <marex@denx.de>