serial: arm_dcc: Remove stdio structure support

Removed stdio structure ops support on arm_dcc
driver, and need to register with serial core
so-that it can access like remianing serial drivers.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>