package/libselinux: install Python modules to target

package/libselinux: install Python modules to target

While LIBSELINUX_INSTALL_STAGING_CMDS uses
$(LIBSELINUX_MAKE_INSTALL_TARGETS), LIBSELINUX_INSTALL_TARGET_CMDS
does not use it. Due to this, the Python module is only installed to
$(STAGING_DIR) and not to $(TARGET_DIR).

Fix this by using $(LIBSELINUX_MAKE_INSTALL_TARGETS) in
LIBSELINUX_INSTALL_TARGET_CMDS.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: James Hilliard <james.hilliard1@gmail.com>
Cc: Matt Weber <matthew.weber@rockwellcollins.com>
Cc: Adam Duskett <aduskett@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>