cpan.bbclass: use '|' as sed separator for entry with paths

cpan.bbclass: use '|' as sed separator for entry with paths

With normal toolchain it works. But fails badly when external Linaro
toolchain is used. And this is why:

-e "s/^\(CCFLAGS =.*\)/\1  -isystem/home/hrw/devel/canonical/aarch64/openembedded/build/linaro-tcwg/gcc-linaro-aarch64-linux-gnu-4.7-2013.04-20130415_linux//aarch64-linux-gnu/include  -O2 -pipe -g -feliminate-unused-debug-types/" \

(From OE-Core rev: f6244a9d3da7c301f19efc114c2aaf39e5eec299)

Signed-off-by: Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>