Make struct renesas_dbsc5_board_config {} definition public via
include/dbsc5.h, so this structure can be defined in board files
and passed into the DBSC5 DRAM driver by overriding weak function
dbsc5_get_board_data() on board level.
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
