Bitfields for OpenHCI "HcRhDescriptorB" register:
Bit(s)	Description	)
 31-16	"PPCM"	PortPowerControlMask -- bitmask of ports NOT affected by global
		  power control (bit 16 [port #0] is reserved)
 15-0	"DR"	DeviceRemovable -- bitmap of removable devices
SeeAlso: #00902,#00915,#00917