target/hexagon: prepare input for the idef-parser

target/hexagon: prepare input for the idef-parser

Introduce infrastructure necessary to produce a file suitable for being
parsed by the idef-parser. A build option is also added to fully disable
the output of idef-parser, which is useful for debugging.

Signed-off-by: Alessandro Di Federico <ale@rev.ng>
Signed-off-by: Anton Johansson <anjo@rev.ng>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20220923173831.227551-8-anjo@rev.ng>