add option to use -pipe

Same as this patch http://review.pac-rom.com/#/c/1008/

Usage:
export TARGET_USE_PIPE=true && ./build-pac.sh

Change-Id: Id5b3ade07364cb5be33172fc7f99f2a6c80b0e63
(cherry picked from commit 56381b1e38eecd128d14e62bdf75d95d7e9e6231)