net: rmnet_data: Add newline character debug packet dump

The lack of newline characters causes messy printouts over serial.
This patch corrects the problem for easier readability.

Change-Id: I38df34eb4a705d8c0fcd3243b7e756967bc7d5a9
Signed-off-by: Harout Hedeshian <harouth@codeaurora.org>