blackfin: serial: Add serial port_fer and port_mux early platform resources.

The serial driver sets up port function manually in early platform probe stage
if the ADI GPIO2 driver is used. Remove the bfin_sport_uart early platform
devices.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>

diff --cc arch/blackfin/mach-bf548/boards/ezkit.c
Simple merge

diff --cc arch/blackfin/mach-bf609/boards/ezkit.c
Simple merge