net: qualcomm: rename qca_framing.c to qca_7k_common.c

As preparation for the upcoming UART driver we need a module
which contains common functions for both interfaces. The module
qca_framing is a good candidate but renaming to qca_7k_common would
make it clear.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>