fotg210-udc: Mask GRP2 interrupts we don't handle

Currently it leaves unhandled interrupts unmasked, but those are never
acked. In the case of a "device idle" interrupt, this leads to an
effectively frozen system until plugging it in.

Fixes: b84a8dee ("usb: gadget: add Faraday fotg210_udc driver")
Signed-off-by: Fabian Vogt <fabian@ritter-vogt.de>
Link: https://lore.kernel.org/r/20210324141115.9384-5-fabian@ritter-vogt.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/fotg210-udc.c

@@ -1026,6 +1026,12 @@ static void fotg210_init(struct fotg210_udc *fotg210)
 	value &= ~DMCR_GLINT_EN;
 	iowrite32(value, fotg210->reg + FOTG210_DMCR);
 
+	/* enable only grp2 irqs we handle */
+	iowrite32(~(DISGR2_DMA_ERROR | DISGR2_RX0BYTE_INT | DISGR2_TX0BYTE_INT
+		    | DISGR2_ISO_SEQ_ABORT_INT | DISGR2_ISO_SEQ_ERR_INT
+		    | DISGR2_RESM_INT | DISGR2_SUSP_INT | DISGR2_USBRST_INT),
+		  fotg210->reg + FOTG210_DMISGR2);
+
 	/* disable all fifo interrupt */
 	iowrite32(~(u32)0, fotg210->reg + FOTG210_DMISGR1);