Update CPU recommendation from 2 GHz to 3 GHz

Align with RavenDB requirements
- https://docs.ravendb.net/7.1/start/installation/system-requirements/

Author: awright18

servicecontrol/servicecontrol-instances/hardware.md

@@ -11,7 +11,7 @@ This article provides recommendations and performance benchmarks to help select
 
 * A dedicated production server for installing ServiceControl instances (Error, Audit, and Monitoring).
 * A minimum of 16 GB of RAM (excluding RAM for OS and other services).
-* 2 GHz quad core CPU or better.
+* 3 GHz quad core CPU or better.
 * A dedicated, non-virtual, pre-allocated SSD for ServiceControl databases (not the disk where the operating system is installed).
 
 ### Scaling ServiceControl