[media] vpdma: remove vpdma_enable_list_notify_irq()

Despite being exported, there's no prototype for it at the
headers, as warned by sparse:

Fixes this sparse warning:
	drivers/media/platform/ti-vpe/vpdma.c:1000:6: warning: no previous prototype for 'vpdma_enable_list_notify_irq' [-Wmissing-prototypes]
	 void vpdma_enable_list_notify_irq(struct vpdma_data *vpdma, int irq_num,
	      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Worse than that, it is not even used, as making it static it
would produce:

	drivers/media/platform/ti-vpe/vpdma.c:1000:13: warning: 'vpdma_enable_list_notify_irq' defined but not used [-Wunused-function]
	 static void vpdma_enable_list_notify_irq(struct vpdma_data *vpdma, int irq_num,
	             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

So, let's just get rid of the dead code. If needed in the future,
someone could re-add it.

Cc: Benoit Parrot <bparrot@ti.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/ti-vpe/vpdma.c

@@ -996,22 +996,6 @@ void vpdma_enable_list_complete_irq(struct vpdma_data *vpdma, int irq_num,
 }
 EXPORT_SYMBOL(vpdma_enable_list_complete_irq);
 
-/* set or clear the mask for list complete interrupt */
-void vpdma_enable_list_notify_irq(struct vpdma_data *vpdma, int irq_num,
-		int list_num, bool enable)
-{
-	u32 reg_addr = VPDMA_INT_LIST0_MASK + VPDMA_INTX_OFFSET * irq_num;
-	u32 val;
-
-	val = read_reg(vpdma, reg_addr);
-	if (enable)
-		val |= (1 << ((list_num * 2) + 1));
-	else
-		val &= ~(1 << ((list_num * 2) + 1));
-	write_reg(vpdma, reg_addr, val);
-}
-EXPORT_SYMBOL(vpdma_enable_list_notify_irq);
-
 /* get the LIST_STAT register */
 unsigned int vpdma_get_list_stat(struct vpdma_data *vpdma, int irq_num)
 {