This patch defines a new opcode in the DEBUG IOCTL that is used by the
user to notify the driver when the user wants to start or stop using the
debug and profile infrastructure of the device. i.e. set the device to
debug mode or to non-debug mode.

There are a couple of restrictions that this new opcode introduces:

1. The user can't configure the debug/profiling infrastructure before he
   sets the device to debug mode, by using this new opcode.

2. The user can't set the device to debug mode unless he is the only user
   that is currently using (has an open FD) the device.

3. Other users can't use the device (open a new FD) in case an existing
   user has set the device into debug mode.

These restrictions are needed because the debug and profiling
infrastructure is a shared component in the ASIC and therefore, can't be
used while multiple users are working on the device.

Because the driver currently does NOT support multiple users, the
implementation of the restrictions is not required at this point. However,
the interface definition is needed in order to avoid changing the user API
later on.
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>