[media] mceusb: report actual tx frequencies

[media] mceusb: report actual tx frequencies

Rather than dumping out hex values, lets print the actual calculated
frequency and period the hardware has been configured for. After this

[ 2643.276215] mceusb 3-1:1.0: tx data: 9f 07 (length=2)
[ 2643.276218] mceusb 3-1:1.0: Get carrier mode and freq
[ 2643.277206] mceusb 3-1:1.0: rx data: 9f 06 01 42 (length=4)
[ 2643.277209] mceusb 3-1:1.0: Got carrier of 37037 Hz (period 27us)

Matches up perfectly with the table in Microsoft's docs.

Of course, I've noticed on one of my devices that the MS-recommended
default value of 1 for carrier pre-scaler and 66 for carrier period was
butchered, and instead of converting 66 to hex (0x42 like above), they
put in 0x66, so the hardware reports a default carrier of 24390Hz.
Fortunately, I guess, this particular device is rx-only, but I wouldn't
put it past other hw to screw up here too.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>