usb: gadget: udc: amd5536udc_pci: Remove unused variable 'mod_desc'

Fixes the following W=1 kernel build warning(s):

 drivers/usb/gadget/udc/amd5536udc_pci.c:52:19: warning: ‘mod_desc’ defined but not used [-Wunused-const-variable=]

Cc: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200706133341.476881-5-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/amd5536udc_pci.c

@@ -49,7 +49,6 @@
 static struct udc *udc;
 
 /* description */
-static const char mod_desc[] = UDC_MOD_DESCRIPTION;
 static const char name[] = "amd5536udc-pci";
 
 /* Reset all pci context */