mhi: dev: uci: do not exceed maximum transfer size supported by mhi host

MHI host doesn't split client packet into multiple descriptors if
size exceed maximum transfer length (mtu) supported by MHI host.
Do not queue buffer bigger than mtu supported by transport layer.

CRs-Fixed: 2254585
Change-Id: I22b0f63c3fadd1600ac795619b98e4c1a9fa3218
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>