Current multiarch directory name is always *-linux-gnu* on linux,
this patch configures different names for uclibc and musl targets.

2017-06-28  Szabolcs Nagy  <szabolcs.nagy@arm.com>

	* config.gcc (*-linux-musl*): Add t-musl tmake_file.
	(*-linux-uclibc*): Add t-uclibc tmake_file.
	* config/t-musl: New.
	* config/t-uclibc: New.

From-SVN: r249745