touchpad_st: "dump_memory" can be enabled via console command

Previously, dump_memory can only be enabled at compile time (through
local build).  Make this runtime configurable.

Currently, it is default off, since dump_memory is very slow and might
not be useful to enable for all users.  The dump log through USB
interface doesn't look good for now.  We revisit the default value in
the future.

BRANCH=nocturne
BUG=b:112877237
TEST=manual on whiskers
Signed-off-by: Wei-Han Chen <stimim@chromium.org>

Change-Id: I422a5a23392298301995df4fbf8101b7a18a62ba
Reviewed-on: https://chromium-review.googlesource.com/1212665
Commit-Ready: Wei-Han Chen <stimim@chromium.org>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1226745
Commit-Queue: Wei-Han Chen <stimim@chromium.org>
1 file changed