dt-bindings: perf: Remove BEAC registers dt bindings from LLCC PMU

This patch removes some of the unnecessary device tree bindings of
BEAC registers from the LLCC PMU driver.

Change-Id: I670719afc9f981ede8255a72a64f8513d3dbca0e
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>