usb: dwc3: fix wrong bit mask in dwc3_event_devt

Around DWC USB3 2.30a release another bit has been added to the
Device-Specific Event (DEVT) Event Information (EvtInfo) bitfield.

Because of that, what used to be 8 bits long, has become 9 bits long.

Per dwc3 2.30a+ spec in the Device-Specific Event (DEVT), the field of
Event Information Bits(EvtInfo) uses [24:16] bits, and it has 9 bits
not 8 bits. And the following reserved field uses [31:25] bits not
[31:24] bits, and it has 7 bits.

So in dwc3_event_devt, the bit mask should be:
event_info	[24:16]		9 bits
reserved31_25	[31:25]		7 bits

This patch makes sure that newer core releases will work fine with
Linux and that we will decode the event information properly on new
core releases.

[ balbi@ti.com : improve commit log a bit ]

Change-Id: I7791c0c266f66f30f7378662e78c0c32d5bf4b6f
Cc: <stable@vger.kernel.org>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>