Fix an unaligned access issue; tidy up OFDM/DS rate decoding from the PLCP.
Fix an unaligned access issue; tidy up OFDM/DS rate decoding from the PLCP.

This fixes a panic on PPC.

Submitted by:	novel
Obtained from:	OpenBSD, sys/dev/ic/bwi.c r1.89

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