Revert "LCD: Add an option to skip registration as an stdio output"

Revert "LCD: Add an option to skip registration as an stdio output"

This reverts commit 05bfe1321024e2ae0039dc16f17d2165610fb4fd.

As discussed on the list, we already have the needed functionality by
defining CONFIG_SYS_CONSOLE_IS_IN_ENV, CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
and adding custom overwrite_console() in the board code.

Signed-off-by: Anatolij Gustschin <agust@denx.de>