NFC: NCI: Handle Discovery deactivation type

When the deactivation type reported by RF_DEACTIVATE_NTF is Discovery, go in
RFST_DISCOVERY state. The NFCC stays in Poll mode and/or Listen mode.

Signed-off-by: Julien Lefrique <lefrique@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>