EDAC, fsl_ddr: Fix IRQ dispose warning when module is removed

When compiled as a module, removing it causes kernel warnings
when irq_dispose_mapping() is called. Instead of calling
irq_of_parse_and_map(), use platform_get_irq() to acquire the IRQ
number.

Signed-off-by: York Sun <[e-mail]>
Cc: linux-edac <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Borislav Petkov <[e-mail]>

drivers/edac/fsl_ddr_edac.c

···
 		ddr_out32(pdata->mc_vbase + FSL_MC_ERR_SBE, 0x10000);
 
 		/* register interrupts */
-		pdata->irq = irq_of_parse_and_map(op->dev.of_node, 0);
+		pdata->irq = platform_get_irq(op, 0);
 		res = devm_request_irq(&op->dev, pdata->irq,
 				       fsl_mc_isr,
 				       IRQF_SHARED,
···
 		if (res < 0) {
 			pr_err("%s: Unable to request irq %d for FSL DDR DRAM ERR\n",
 			       __func__, pdata->irq);
-			irq_dispose_mapping(pdata->irq);
 			res = -ENODEV;
 			goto err2;
 		}
···
 	edac_dbg(0, "\n");
 
 	if (edac_op_state == EDAC_OPSTATE_INT) {
-		irq_dispose_mapping(pdata->irq);
 		ddr_out32(pdata->mc_vbase + FSL_MC_ERR_INT_EN, 0);
 	}