nand: move in driver.h the nand_flash_controller's declaration
The static analyser 'sparse' complains, while compiling a nand
driver, that the struct nand_flash_controller is declared in the
file as non static, but it is not exposed through an include file.
The message is:
warning: symbol 'XXX' was not declared. Should it be static?
Move the list of nand_flash_controller's declaration in driver.h
While there, drop the unused/commented boundary scan controller.
Change-Id: I7dc32cef55be13ba537abe0f4c47b135d837126c
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7661
Tested-by: jenkins