Bitfields for PCI Power Management PMCSR bridge support extension:
Bit(s)	Description	)
 7	(read-only) Bus Power Control Enable
 6	(read-only) Bus Power State B3 supported
 5	(read-only) Bus Power State B2 supported
 4	dynamic clock control enable
 3-0	reserved (0)
Note:	this information is from the v0.93 draft of the specification and is
	  subject to change
SeeAlso: #00884,#00885,#00886