toolchain: Move extra warning options to toolchain abstraction

Move extra warning option from generic twister script into
compiler-dependent config files.
ARCMWDT compiler doesn't support extra warning options ex.
"-Wl,--fatal-warnings". To avoid build fails flag
"disable_warnings_as_errors" should be passed to twister.
This allows all warning messages and make atomatic test useles.

Signed-off-by: Nikolay Agishev <agishev@synopsys.com>
(cherry picked from commit 0dec4cf9)