test: physical: Capture Action::Blink parameters

Implement value sensing to verify behaviour of the blink action. This
constrains future blink changes to interacting with sysfs in the same
manner.

Change-Id: I7ed0a5d52e8dc99192e7938760ce99f618b9cb16
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
1 file changed