There's no way to do this directly but, as usual, there's a workaround.
Go to the page you want to set as your homepage. Touch the 'curly arrow' icon on the Safari menu bar and choose 'Add to Home Screen'. That link will now be added as an icon to your Home screen. Now, when you want to access Safari, touch that icon instead of the Safari icon. Safari will open and take you directly to your 'home screen'....
Tim