Michael Brown
c742c576d0
[build] Move predefined all-drivers build shortcut to Makefile
The (very approximate) split between Makefile.housekeeping and
Makefile is that the former provides mechanism and the latter provides
policy.
Provide a section within Makefile as a home for predefined build
shortcuts such as the existing all-drivers build.
Signed-off-by: Michael Brown <mcb30@ipxe.org>