tools: ynl: add main install target

tools: ynl: add main install target

This will install C library, specs, rsts and pyynl. The initial
structure is:

	$ mkdir /tmp/myroot
	$ make DESTDIR=/tmp/myroot install

	/usr
	/usr/lib64
	/usr/lib64/libynl.a
	/usr/lib/python3.XX/site-packages/pyynl/*
	/usr/lib/python3.XX/site-packages/pyynl-0.0.1.dist-info/*
	/usr/bin
	/usr/bin/ynl
	/usr/bin/ynl-ethtool
        /usr/include/ynl/*.h
	/usr/share
	/usr/share/doc
	/usr/share/doc/ynl
	/usr/share/doc/ynl/*.rst
	/usr/share/ynl
	/usr/share/ynl/genetlink-c.yaml
	/usr/share/ynl/genetlink-legacy.yaml
	/usr/share/ynl/genetlink.yaml
	/usr/share/ynl/netlink-raw.yaml
	/usr/share/ynl/specs
	/usr/share/ynl/specs/devlink.yaml
	/usr/share/ynl/specs/dpll.yaml
	/usr/share/ynl/specs/ethtool.yaml
	/usr/share/ynl/specs/fou.yaml
	/usr/share/ynl/specs/handshake.yaml
	/usr/share/ynl/specs/mptcp_pm.yaml
	/usr/share/ynl/specs/netdev.yaml
	/usr/share/ynl/specs/net_shaper.yaml
	/usr/share/ynl/specs/nfsd.yaml
	/usr/share/ynl/specs/nftables.yaml
	/usr/share/ynl/specs/nlctrl.yaml
	/usr/share/ynl/specs/ovs_datapath.yaml
	/usr/share/ynl/specs/ovs_flow.yaml
	/usr/share/ynl/specs/ovs_vport.yaml
	/usr/share/ynl/specs/rt_addr.yaml
	/usr/share/ynl/specs/rt_link.yaml
	/usr/share/ynl/specs/rt_neigh.yaml
	/usr/share/ynl/specs/rt_route.yaml
	/usr/share/ynl/specs/rt_rule.yaml
	/usr/share/ynl/specs/tcp_metrics.yaml
	/usr/share/ynl/specs/tc.yaml
	/usr/share/ynl/specs/team.yaml

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Link: https://patch.msgid.link/c882688d751295c7f35c7d4eba104cd5174a0861.1736343575.git.jstancek@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>