qmsi: aon counter: Use locking mechanism to guard critical regions of API call

This will guard critical regions in the driver API so that the API
operation called from one thread (task or fiber) can complete
without the context being over-written by any simultaneous call
of the API from other thread (task or fiber).

The locking mechanism is by default disabled in the build. To enable it,
the following flag needs to be defined:

CONFIG_AON_API_REENTRANCY

Jira: ZEP-424
Change-Id: I1b0eae70a4ab97229931033153662874d7c4a68e
Signed-off-by: Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>