Add all relevant testcases for Arm Ethos-U85 (#5346)

Summary:
Add separate tests for Ethos-U85 to all backend operator tests.
Updated ethos-u-vela version to support more operators.

Signed-off-by: Per Åstrand <[per.astrand@arm.com](mailto:per.astrand@arm.com)>
Signed-off-by: Tom Allsop <[tom.allsop@arm.com](mailto:tom.allsop@arm.com)>

Pull Request resolved: https://github.com/pytorch/executorch/pull/5346

Reviewed By: manuelcandales

Differential Revision: D62875027

Pulled By: digantdesai

fbshipit-source-id: 3bf238d81957258ee93ae235d575beff8a575191