libgomp: Remove unused '--with-hsa-runtime', '--with-hsa-runtime-include', '--with...

libgomp: Remove unused '--with-hsa-runtime', '--with-hsa-runtime-include', '--with-hsa-runtime-lib'

With recent commit 2e309a4eff80e55b53d32d26926a2a94eabfea21 "libgomp testsuite:
Don't amend 'LD_LIBRARY_PATH' for system-provided HSA Runtime library",
and commit d6adba307508c75f1ccb2121eb1a43c9ab1d4056 "libgomp GCN plugin:
 Clean up unused references to system-provided HSA Runtime library", the last
uses of '--with-hsa-runtime' etc. are gone.

	gcc/
	* doc/install.texi: Don't document '--with-hsa-runtime',
	'--with-hsa-runtime-include', '--with-hsa-runtime-lib'.
	libgomp/
	* plugin/configfrag.ac: Remove '--with-hsa-runtime',
	'--with-hsa-runtime-include', '--with-hsa-runtime-lib' processing.
	* Makefile.in: Regenerate.
	* configure: Likewise.
	* testsuite/Makefile.in: Likewise.