dt-bindings: devfreq: Add DT bindings to configure byte MID match

This patch adds DT bindings for configuring the byte MID Match in
BWMON driver.

Change-Id: Ie39df60c96bb79d36d2638b810755356ff57dd09
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>