python3: do not replace ccache in the middle of a path
Python recipe did a sed s/ccache/$(CCACHE) on the Makefile, which
replaces all "ccache" including ones that consist of a full path.
This leads to build error when building in a project path with
"ccache" in its name. Fix it by only replacing "ccache " with
"$(CCACHE) ".
Same fix on python 2.xx is:
1181112cf65bc[python: do not replace ccache in the ]
Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
