arm: xea: dts: Add 'fec-3v3' regulator properties to prevent accidental disablement

arm: xea: dts: Add 'fec-3v3' regulator properties to prevent accidental disablement

The 'enable-active-high' DTS property configures GPIO so it is active with
HIGH state (by default it is low).

The 'regulator-boot-on' property indicates that the regulator was enabled
in the 'earlier' stage - i.e. bootloader/firmware.
In the XEA case the 'fec-3v3' was configured (as a "wrapper" on GPIO0_0) in
very early SPL code, so it shouldn't be modified at latter stages.

Signed-off-by: Lukasz Majewski <lukma@denx.de>