Refactoring HAL LCD component

Refactoring the LCD implementation under HAL to remove
unrequired redirection and briging it in line with the
camera and audio interfaces. Renaming `lcd` as a `display`
component to make it generic, in preparation for support
to be added for Arm Corstone-315 and Corstone-320 targets
in later patches.

Change-Id: I7da4d9c5ec91d2aa5ee3af7133575c47c06cae88
Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>