treewide: move nand_do_upgrade call to platform_do_upgrade
Calling nand_do_upgrade() from platform_pre_upgrade() was deprecated
with 30f61a34b4cf ("base-files: always use staged sysupgrade").
Update the platform upgrade code to use platform_do_upgrade() for NAND
images as well.
Signed-off-by: Mathias Kresin <[email protected]>