usb: chipidea: remove zero check of hw_ep_max

It's 0 for host only device.

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>