package_manager: Create variable for install_dir_name
This patch creates a variable for the install_dir name so it can be
something other than /install, also by doing this we can correctly
clean up the empty directories (/install/tmp) during the clean-up
phase. The new default is /oe_install so as to not conflict with other
possible packages that might use /install to place files.
[YOCTO #7353]
Signed-off-by: Saul Wold <sgw@linux.intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
