drivers: power: reset: Do warm reset when device reboot to edl

Device reboot to edl, it's for switching device to emergency dload mode.
So it's need to keep device to do warm reset.

Change-Id: I8f5d0845c6f2d37ea740949ce56e02c4cc7412be
Signed-off-by: Lijuan Gao <lijuang@codeaurora.org>