msm: mdss: Add panel-name in msm_fb_panel_info sysfs node

To support per-panel tuning during run-time, panel name/id needs
to expose to tuning service in userspace, so tuning service can
apply proper tuning configs against different panels detected
dynamically via LK bootloader.

Change-Id: I193bb375495ea0963560ea698881176b52727d62
Signed-off-by: Zohaib Alam <zalam@codeaurora.org>