usb: hcd.h: construct hub class request constants from simpler constants

usb: hcd.h: construct hub class request constants from simpler constants

Currently, each hub class request constant is defined by a line like:
#define ClearHubFeature		(0x2000 | USB_REQ_CLEAR_FEATURE)

The "magic" number for the high byte is one of 0x20, 0xa0, 0x23, 0xa3.
The 0x80 bit that changes inditace USB_DIR_IN, and the 0x03 that
pops up is the difference between USB_RECIP_DEVICE (0x00) and
USB_RECIP_OTHER (0x03). The constant 0x20 bit is USB_TYPE_CLASS.

This patch eliminates those magic numbers by defining a macro to help
construct these hub class request from simpler constants.
Note that USB_RT_HUB is defined as (USB_TYPE_CLASS | USB_RECIP_DEVICE)
and that USB_RT_PORT is defined as (USB_TYPE_CLASS | USB_RECIP_OTHER).

Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>