misc: xilinx_sdfec: Store driver config and state

misc: xilinx_sdfec: Store driver config and state

Stores configuration based on parameters from the DT
node and values from the SD-FEC core plus reads
the default state from the SD-FEC core. To obtain
values from the core register read, write capabilities
have been added plus related register map details.

Tested-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Signed-off-by: Derek Kiernan <derek.kiernan@xilinx.com>
Signed-off-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Link: https://lore.kernel.org/r/1564216438-322406-2-git-send-email-dragan.cvetic@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>