The fiq NMI calls rand() from lmac:lmac.a:sdk_lmacTxFrame and the NMI
must not touch the newlib reent structure or enter critical regions
etc, so just use the simple and safe hwrand implementation as a
substitute.
To keep things from changing out from under us as we slowly replace bits of the
SDK libs, changing Makefiles to not auto-generate the list of symbols to
rename, but always use the same list every time.
