qcom-dload-mode: Convert reboot notifier to restart notifier

There could be chance of edl download mode written by qcom-dload-mode
driver overwritten by Scm device shutdown call as the reboot notifiers
gets called prior to device_shutdown in reboot path.

To fix this convert the reboot notifiers to restart notifiers and keep
its priority higher than scm restart handler so that warm reboot_mode
set here should be seen by SCM restart handler (priority 130).

Change-Id: I2daa41d04788e525f274323e9c815bf10cb79ed2
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>