test: physical: Introduce LED mocks

This removes the dependency on touching the filesystem entirely. All
methods are now mocked into an ignored state when called by the NiceMock
template class. The filesystem is only touched by the SysfsLed tests,
though we still need to provide a temporary path to its constructor in
the decended mock class to ensure we're isolated if something does
manage to get written.

Change-Id: I3955a6e0fb5c3c42887da847239d381ef151fa3e
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
1 file changed