msm: smp: Remove WFE/SEV from secondary core bootup

During the cold boot path once the secondary core is released
out of reset we keep looping for the pen release variable.
The wfe+sev in this path are just unnecessary as they provide
negligible power savings, and the latency cost is not worth it.
During the hotplug path the secondary core will be in wfi and
only an interrupt will be able to bring the core out.
Removing the wfe effectively lowers the hotplug latency.

Change-Id: Ic54636ceafb8abf3b6733e5699733543d64776d5
Signed-off-by: Taniya Das <tdas@codeaurora.org>