Marvell nfc device provides support for external coexistance
control. It allows Device Host to inhibit the NFCC from polling
when required by asserting a GPIO pin. A second pin allows the
DH to have feedback on the current NFCC state.

The required configuration for this feature is done in setup
handler.
Signed-off-by: NAmitkumar Karwar <akarwar@marvell.com>
Signed-off-by: NBing Zhao <bzhao@marvell.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>