USB: EHCI: EHCI 1.1 addendum: Enable Per-port change detect bits

This patch will enable Per-port event feature defined in EHCI 1.1
addendum. This feature addresses an issue where HCD is currently
required to read and parse PORTSC for all enabled root hub ports. With
this patch, the overhead will be reduced.

Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 21f30a0..e6c57cc 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -141,6 +141,7 @@
 	__hc32			*ohci_hcctrl_reg;
 	unsigned		has_hostpc:1;
 	unsigned		has_lpm:1;  /* support link power management */
+	unsigned		has_ppcd:1; /* support per-port change bits */
 	u8			sbrn;		/* packed release number */
 
 	/* irq statistics */