Bitfields for OpenHCI "HcRhDescriptorA" register:
Bit(s)	Description	)
 31-24	"POTPGT" power-on to power-good time in 2ms units
 23-13	reserved
 12	"NOCP"	no over-current protection supported
 11	"OCPM"	over-current status reported per-port
 10	"DT"	device type - is root hub compound device?
 9	"NPS"	NoPowerSwitching -- ports are always powered up
 8	"PSM"	power-switching mode -- if set, each port powered individually
 7-0	"NDP"	number of downstream ports
SeeAlso: #00902,#00916,#00917