msm: ep_pcie: Perform pcie controller reset before MHI mmio restore

PCIE controller reset is done before MHI mmio registers are restored
to avoid enumeration issues in host-reboot scenario.

Change-Id: Ife5f37dc32f9023f5e3d32131269cfa91c0eca5b
Signed-off-by: Siva Kumar Akkireddi <sivaa@codeaurora.org>