[media] msi3101: change stream format 384

After feeding different signal levels using RF generator and looking
GNU Radio FFT sink I made decision to change bit shift 3 to bit shift
2 as there was very (too) huge visible leap in FFT sink GUI. Now it
looks more natural.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>