board/BuR/common: make CONFIG_LCD optional

Since we're going to drop LCD-support on brppt1 boards, we have to make
this stuff here optional and remove the #error path.

We also move out the ft_board_setup(...) from this #ifdef because
there's no relationship with the LCD-code and on the other hand this is
still needed in future even with LCD-support off.

Signed-off-by: Hannes Schmelzer <oe5hpm@oevsv.at>