EFI_CONSOLE_CONTROL_PROTOCOL provide the SetMode interface to switch mode between...

	EFI_CONSOLE_CONTROL_PROTOCOL provide the SetMode interface to switch mode between EfiConsoleControlScreenText and EfiConsoleControlScreenGraphics. And implementation of this interface is in EdkModlePkg\Universal\Console\ConSplitter\Dxe\ConSplitterGraphices.c ConSpliterConsoleControlSetMode().
	In this function, it is better to judge current mode with wanted mode at first, if current mode is equal to wanted mode, then return and do nothing. Why need add judging:
	1) Missing judge will lead an issue that screen splash when pressing key in front page. It is caused by ui.c will switch to textmode when first in, but current mode has been in text mode.
	2) If switching to text mode, there are many works want to be done such as EnableCursor, ClearScreen. If original has been in text mode, judging will improve the performance of UI.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@2345 6f19259b-4bc3-4df7-8a09-765794883524