opkg.inc: don't hardcode /var/lib/opkg

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
wayland: add necessary dependencies to fix build error

add libffi into DEPENDS to fix following build error:
| checking for FFI... no
| configure: error: Package requirements (libffi) were not met:
|
| No package 'libffi' found

Signed-off-by: Zhenhua Luo <zhenhua.luo@freescale.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>