drivers: ethernet: imx_netc: add netc block driver

Add NETC block driver, it could do some block memory region MMIO mapping
and also so dome block initialization, moved some netc related
configuration form board_init() to block driver so that it could be reused
between different platforms, although some configuration is different for
different platform, but put all NETC related code in the same driver to
make it easier to be maintained.

Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>