arm: socfpga: Add function for checking description from FIT image

Add board_fit_config_name_match() for matching board name with
device tree files in FIT image. This will ensure correct DTB
file is loaded for different board type. Currently, we are not
supporting multiple device tree files in FIT image therefore this
function basically do nothing for now.
Users are allowed to override this 'weak' function in their
specific board implementation.

Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>