The iflib stack failed to release all of the memory allocated under
M_IFLIB during device detach.
Specifically, the ifmp_ring, the ift_ifdi Tx DMA info, and the ifr_ifdi Rx
DMA info were not being released.
Release this memory so that iflib won't leak memory when a device
Since we're freeing the ift_ifdi pointer during iflib_txq_destroy we
need to call this only after iflib_dma_free in iflib_tx_structures_free.
Additionally, also ensure that we destroy the callout mutex associated
with each Tx queue when we free it.
Signed-off-by: Jacob Keller <email@example.com>