ccache.bbclass: use ccache from host distribution

ccache 4.x has hard dependencies on cmake-native (used as
build system) and zstd, which means inserting ccache-native
as DEPENDS into everything creates circular dependencies which
are impossible to break.

ccache 3.x did not have this problem as it used plain makefiles
and an in-tree copy of zlib.

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>