msm: kgsl: Set isdb breakpoints before snapshot

When taking a scandump, set isdb breakpoints to have same data as snapshot.
Also provide a sysfs knob to control the breakpoint set.

Change-Id: I0d27cff15ff9f93c78e8b58899e794dfabcb8d79
Signed-off-by: Mohammed Mirza Mandayappurath Manzoor <mmandaya@codeaurora.org>