soc: qcom: make debugfs support configurable for kryo l2 accessors driver

Add config option to enable/disable l2 indirect access debug capability.
The driver exposes l2 indirect access debugfs interface to get/set data,
address, and target cpus so keep it disabled by default.

Change-Id: I22f84d16a3bf12a78295f2d052bb50e90d6f2a8b
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>