iwlwifi: dbg: fix debug monitor stop and restart delays

The driver should delay only in recording stop flow between writing to
DBGC_IN_SAMPLE register and DBGC_OUT_CTRL register. Any other delay is
not needed.

Change the following:
1. Remove any unnecessary delays in the flow
2. Increase the delay in the stop recording flow since 100 micro is
   not enough
3. Use usleep_range instead of delay since the driver is allowed to
   sleep in this flow.

Signed-off-by: Shahar S Matityahu <shahar.s.matityahu@intel.com>
Fixes: 5cfe79c8 ("iwlwifi: fw: stop and start debugging using host command")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>