staging: rtl8723au: Remove a bunch of calls via indirect HAL interface and call functions directly

The 'HW' variable interface is confusing and simply obfuscates the
code, so this is the first patch in a series to remove it and make
direct calls to the functions in place.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>