dt-bindings: devfreq: Add dt-bindings for BWMON HW version 5

This patch adds the dt-bindings for the version 5 of the BIMC
BWMON HW.

Change-Id: Ibfeeaaf07153173e30caf3ab74c8e4852efe62be
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>