input: synaptics_fw_update: Add package ID support

Add ability to read package id from sysfs.  Also, only
update firmware when package id of image header file
matches package id on device, except in "force" mode.

This patch is propagated from msm-3.4 kernel.
(commit: 2c4c48ca2240b1bbb05fa956097ddd8e51afb8c0
input: synaptics_fw_update: Add package ID support)
Also cleaned checkpatch warnings on msm-3.18 kernel.

Change-Id: I8473508cddcacbd13a580324b6c74ca80ac9d646
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>
Signed-off-by: Sudhakar Manapati <smanap@codeaurora.org>