m25p80: wait for flash before returning after erase
else when we do "erase /dev/m25p0.rootfs; reset", the board
will never reboot as the flash is busy to finish the erase
command.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>