toolchain: remove hardcoded compiler versions

When the SDK is updated usually it comes with new versions of the
compiler causing issues with the toolchain not finding libraries.

This will get the version from the compiler and sets the path
accordingly.

Change-Id: I854c57bb082ae8136eebdd0ae7a8c151c1d699c8
Signed-off-by: Anas Nashif <anas.nashif@intel.com>