misc: xilinx_sdfec: Add ability to configure turbo

misc: xilinx_sdfec: Add ability to configure turbo

Add the capability to configure and retrieve turbo mode
via the ioctls XSDFEC_SET_TURBO and XSDFEC_GET_TURBO.
Add char device interface per DT node present and support
file operations:
- open(),
- close(),
- unlocked_ioctl(),
- compat_ioctl().

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/1564216438-322406-3-git-send-email-dragan.cvetic@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>