libpayload: Add support for split transactions in EHCI

With split transactions, the EHCI host controller can handle full- and
low-speed devices on hubs in high-speed mode. This adds support for split
transactions for control and bulk transfers.

Change-Id: I30fa1ce25757f33b1e6ed34207949c9255f05d49
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1081
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

payloads/libpayload/drivers/usb/ehci_private.h

@@ -116,6 +116,8 @@ typedef volatile struct {
 #define QH_NON_HS_CTRL_EP_SHIFT 27
 #define QH_NAK_CNT_SHIFT 28
 	u32 epcaps;
+#define QH_HUB_ADDRESS_SHIFT 16
+#define QH_PORT_NUMBER_SHIFT 23
 #define QH_PIPE_MULTIPLIER_SHIFT 30
 	volatile u32 current_td_ptr;
 	volatile qtd_t td;