Fix for using the .pc file when cross-compiling.

Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

Added PKG_BUILD_PARALLEL for faster building.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Fixes the following build error:
hiredis.h:101:24: error: lvalue required as left operand of assignment
             buf[(len)] = '\0';

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>