Makefile: Allow CRT0 and LDSCRIPT to be overridden

Different distributions have a habit of installing the gnu-efi crt0
and ldscripts in various locations on the file system. Until efilinux
gets autoconf support allow the user to override $CRT0 and $LDSCRIPT.

Signed-off-by: Matt Fleming <matt.fleming@intel.com>
1 file changed