MFC r313554:
Clean redundant MIN/MAX declarations in some HighPoint drivers.

The hpt27xx(4), hptnr(4), and hptrr(4) drivers declare MIN() and MAX()
internally which match the macros from sys/param.h.

MIN() is not used, MAX is only used once and can be replaced with the
max() version in libkern.h which operates on u_ints.

MFC after: 2 weeks