msm: peripheral-loader: Move proxy voting to before init_image

Some PIL devices may use init_image to bring their
processor/subsystem out of reset, e.g. devices that
do self authentication. Move proxy voting to before
init_image to support this.

Change-Id: Ic99abb357ab1fb20a1d421c491fa81fa9c71fa9e
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>