libkmod: Add ELF note for openssl library

libkmod: Add ELF note for openssl library

Follow the new spec for ELF notes as detailed in
https://systemd.io/ELF_PACKAGE_METADATA/.

We can copy mostly verbatim the macros from systemd codebase.

Example output:

	$ meson setup --native-file build-dev.ini -Ddlopen=openssl build
	...
	    dlopen           : openssl

	    features         : +ZSTD +XZ +ZLIB +OPENSSL

	$ dlopen-notes.py build/libkmod.so.2
	# build/libkmod.so.2
	[
	  {
	    "feature": "openssl",
	    "description": "Support for reading module signatures",
	    "priority": "suggested",
	    "soname": [
	      "libcrypto.so.3"
	    ]
	  }
	]

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/420
Signed-off-by: Lucas De Marchi <demarchi@kernel.org>