mhi: core: Enable mhi_dev_net interface channels

Enable 46, 47 channels for mhi_dev_net interface.
mhi_dev_net client uses read and write channels to
communicate mhi host rmnet interface over PCIe link.

CRs-Fixed: 2029099
Change-Id: Ifdda4b1a139751bd2b36143d9125068f34fec9e5
Signed-off-by: Prasad Malisetty <prasadm@codeaurora.org>