USB: EHCI: EHCI 1.1 addendum: preparation

USB: EHCI: EHCI 1.1 addendum: preparation

EHCI 1.1 addendum introduced several energy efficiency extensions for
EHCI USB host controllers:
1. LPM (link power management)
2. Per-port change
3. Shorter periodic frame list
4. Hardware prefetching

This patch is intended to define the HW bits and debug interface for
EHCI 1.1 addendum. The LPM and Per-port change patches will be sent out
after this patch.

Signed-off-by: Jacob Pan <[email protected]>
Signed-off-by: Alek Du <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>