Delete PROGRESS macros

I don't see much point in cluttering the source with the PROGRESS
macros, which of course do nothing at all with the definitions in
progress.h.  progress.h is unchanged apart from the copyright comment
since commit d4d4c53c in 1994.

binutils/
	* ar.c: Don't include progress.h, or invoke PROGRESS macros.
	* nm.c: Likewise.
	* objcopy.c: Likewise.
	* objdump.c: Likewise.
gas/
	* as.h: Don't include progress.h.
	* as.c: Don't invoke PROGRESS macros.
	* write.c: Likewise.
include/
	* progress.h: Delete.
ld/
	* ldmain.c: Don't include progress.h, or invoke PROGRESS macros.