intel: tools: dump: remove command execution feature

intel: tools: dump: remove command execution feature

In commit 86cb05a6d35a52 ("intel: aubinator: remove standard input
processing option") we removed the ability to process aub as an input
stream because we're now rely on mmapping the aub file to back the
buffers aubinator is parsing.

intel_aubdump was the provider of the standard input data and since
we've copied/reworked intel_aubdump into intel_dump_gpu within Mesa,
we don't need that code anymore.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>