Fix compiler prefix extraction in newlib external

Change the regex based solution to handle arbitrary number of parts in
the compiler prefix. The previous regex only allowed triplets which
caused problems with compilers like aarch64-none-linux-gnu-gcc.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I55247c0fd5223728d08c8537a16c456398dd2bd1
1 file changed