V4L/DVB: Add FE_CAN_TURBO_FEC

Some (North American) providers use a non-standard mode called
"8psk turbo fec". Since there is no flag in the driver that
would allow an application to determine whether a particular
device can handle "turbo fec", the attached patch introduces
FE_CAN_TURBO_FEC.

Since there is no flag in the SI data that would indicate
that a transponder uses "turbo fec", VDR will assume that
all 8psk transponders on DVB-S use "turbo fec".

Tested-by: Derek Kelly <[e-mail]>
Signed-off-by: Klaus Schmidinger <[e-mail]>
Signed-off-by: Douglas Schilling Landgraf <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/dvb/dvb-usb/gp8psk-fe.c

···
 			 * FE_CAN_QAM_16 is for compatibility
 			 * (Myth incorrectly detects Turbo-QPSK as plain QAM-16)
 			 */
-			FE_CAN_QPSK | FE_CAN_QAM_16
+			FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_TURBO_FEC
 	},
 
 	.release = gp8psk_fe_release,

include/linux/dvb/frontend.h

···
 	FE_CAN_8VSB			= 0x200000,
 	FE_CAN_16VSB			= 0x400000,
 	FE_HAS_EXTENDED_CAPS		= 0x800000,   /* We need more bitspace for newer APIs, indicate this. */
+	FE_CAN_TURBO_FEC		= 0x8000000,  /* frontend supports "turbo fec modulation" */
 	FE_CAN_2G_MODULATION		= 0x10000000, /* frontend supports "2nd generation modulation" (DVB-S2) */
 	FE_NEEDS_BENDING		= 0x20000000, /* not supported anymore, don't use (frontend requires frequency bending) */
 	FE_CAN_RECOVER			= 0x40000000, /* frontend can recover from a cable unplug automatically */