common/lcd code is full of platform-specific code and definitions, which
ideally should reside with the respective driver code. Take a step towards that
goal by moving platform-specific structs from lcd.h to their own header files.

The structs for the generic case (the #else for all the platform-specific
cases) is retained in lcd.h as the default case.

Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Bo Shen <voice.shen@atmel.com>
Tested-by: Josh Wu <josh.wu@atmel.com>
Cc: Bo Shen <voice.shen@atmel.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Anatolij Gustschin <agust@denx.de>