rules_mk: don't include wrapped bin with external toolchains

rules_mk: don't include wrapped bin with external toolchains

Don't add wrapped bin to the TARGET_PATH as it does cause compilation
error.

cmake.mk will use the "command -v" and will use the wrapped bin instead
of the external toolchain bin as they have the same name and command
will select the first result.

Signed-off-by: Christian Marangi <[email protected]>
(cherry picked from commit a90eabf60255773231ed0259e5da5eb6a36fe9ce)