vendor: Drop verity tool

Disabling AVB (1.0 & 2.0) is now done with flags in board and in kernel.
In both cases, it's done device-side by default.
Henceforth, drop the tool as isn't even built nor shipped.

Reference:
[0]: https://review.lineageos.org/q/If1d641c8ce4598864a9aa6f23dbf2ac7bdddd4cf
[1]: https://review.lineageos.org/q/I381feef8f6fefc8449ca50d85d704b67bcc8a77e
[2]: https://review.lineageos.org/q/I97f1169a7cfccc78530b9869a407b3a9eade31ab



Signed-off-by: Aayush Gupta <aayushgupta219@gmail.com>
Change-Id: If39f2b943b8af83ded6b183738f2f4e91cab13be