tools: tests: accept the new gpio-sim label format in test cases

tools: tests: accept the new gpio-sim label format in test cases

Since kernel commit 840a97e2fbaf ("gpio: sim: delimit the fwnode name
with a ":" when generating labels") the gpio-sim automatic labels are
generated by delimiting the device name and the fwnode name with ':'
instead of '-' for better readability. This will break the tests once
linux v6.9 is out. Act in advance and accept both forms.

Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20240506162506.176935-1-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>