scripts/tags.sh: Include tools directory in tags generation

scripts/tags.sh: Include tools directory in tags generation

Add tools directory in generating tags and quiet the "No such file or
directory" warnings.

It reverts the changes introduced in commit 162343a876f1
("scripts/tags.sh: exclude tools directory from tags generation") while
maintainig the original intent of the patch to get rid of the warnings.
This allows the root level cscope files to include tools source code
besides kernel and a single place to browse the code for both.

Acked-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Signed-off-by: Vipin Sharma <vipinsh@google.com>
Link: https://lore.kernel.org/r/20220618005457.2379324-1-vipinsh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>