In Desktop Firefox right-click the page and choose "Show page info". Go to Permissions and find Share location.
In Desktop Chrome go to url chrome://settings/content, find Location and click Manage exceptions.
In Android Chromium (default Android browser; usually called "Browser" or "Internet") you must go to Settings > Privacy > Remove private date, check Location access and click OK.
In Android Chrome open Menu (HW button or top-right button) and go to Settings > Advanced > Content settings > Website settings and uncheck Location access under for each website you want to reset the settings.
For Android Firefox go to the page with location access and long press the URL bar (it have to be highlighted while you press it). In popup menu choose Edit site settings, check the Share location and click Clear.
And in Android Opera you must delete all web data (Menu > Settings > Clear Browsing data > Clear Cookies and Data).
Other browsers (e.g. Internet Explorer, Safari, etc.) does not allow to remember this or does not allow to remove the permission.