Including config.h as first is required for every C file.
Add it to the C files that still miss it.
Change-Id: I1a210e7d3a854958a85a290b086ad8a9f5176425
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6856
Tested-by: jenkins