Fix the flags to bus_dmamem_* to allow the allocation to sleep while waiting for resources.  It is really the load that we can't defer. BUS_DMA_NOCACHE belongs on bus_dmamap_load() as well.
Fix the flags to bus_dmamem_* to allow the allocation to sleep while
waiting for resources.  It is really the load that we can't defer.
BUS_DMA_NOCACHE belongs on bus_dmamap_load() as well.

MFC after:	3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase