Add an option to override the reconcile SyncPeriod

[mkumatag]

/kind feature
/area provider/ibmcloud

Describe the solution you'd like
Currently, syncPeriod is hardcoded and set as 15 seconds which is too little and causes the burden on the cloud, may also hit the rate limit, hence need a mechanism to override the value and set a decent value as default.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]