HP SmartArray Controllers usually allow to reconfigure the RAID if BBWC/FBWC is present and fully charged.
After expanding the RAID you may need to create a new logical volume for rather than expanding the existing one. VMware does not support increasing a local VMFS datastore from the GUI and you'd have to do this manually from the command line, if you decide to increase the existing volume anyway (see e.g. http://communities.vmware.com/thread/335302).
Please also keep in mind, that due to a driver issue, you may still be limited to a logical volume size of ~2TB with some SmartArray Controllers (although ESXi 5 supports up to ~64TB). see http://kb.vmware.com/kb/2006942
André