Changes to PRIVATE_LIBS should change the sstate checksum. To make
that happen, it needs to be listed in the list of package specific
variables, therefore add it.
(From OE-Core rev: 1a6555dfd17e180b81dec407095787d8a72a9edd)
Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>