Mboot now supports FAT, LFS1 and LFS2 filesystems, to load firmware from.
The filesystem needed by the board must be explicitly enabled by the
configuration variables MBOOT_VFS_FAT, MBOOT_VFS_LFS1 and MBOOT_VFS_LFS2.
Boards that previously used FAT implicitly (with MBOOT_FSLOAD enabled) must
now add the following config to mpconfigboard.h:
#define MBOOT_VFS_FAT (1)
Signed-off-by: Damien George <damien@micropython.org>