Bitfields for OpenHCI "HcHCCA" register:
Bit(s)	Description	)
 31-8	physical address of Host Controller Communications Area (bits 31-8)
 7-0	reserved (0)
Note:	the required alignment for the HCCA may be determined by writing
	  FFFFFFFFh to this register and determining the number of low-order
	  zero bits
SeeAlso: #00902,#00909,#00910