Octeontx2-vf: Fix max packet length errors

Octeontx2-vf: Fix max packet length errors

Once driver submits the packets to the hardware, each packet
traverse through multiple transmit levels in the following
order:
	SMQ -> TL4 -> TL3 -> TL2 -> TL1

The SMQ supports configurable minimum and maximum packet sizes.
It enters to a hang state, if driver submits packets with
out of bound lengths.

To avoid the same, implement packet length validation before
submitting packets to the hardware. Increment tx_dropped counter
on failure.

Fixes: 3184fb5ba96e ("octeontx2-vf: Virtual function driver support")
Fixes: 22f858796758 ("octeontx2-pf: Add basic net_device_ops")
Fixes: 3ca6c4c882a7 ("octeontx2-pf: Add packet transmission support")
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Link: https://patch.msgid.link/20250821062528.1697992-1-hkelam@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>