PIP_INSTALL_PACKAGE isn't used anymore, so remove all instances of it
from the recipes.
(From OE-Core rev: 15baf24f750ab2c8b0a46d4a3bf2ae9bfa3d0aff)
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>