update oemcommands.hpp to use new API

All the command handler numbers and netfn numbers were done
using the old API. This updates all the enums to be ipmi::Cmd
or ipmi::NetFn types. This improves readability by eliminating
unneeded static_casts and brings the legacy code to the present.

One minor fix, otherwise the code is the same. The call to
registerFilter was passing a netfn instead of a priority. It compiled
but it was incorrect. This updates it to use the correct parameter.

Tested: builds and produces the same binary output (other than the
    aforementioned registerFilter fix)

Change-Id: I7e83123245b3f340088f8ec75a31b7611d0ecda0
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
11 files changed