mmc: pxamci: better pending IRQ determination

Pending interrupts should be determined from both I_REG and I_MASK
registers.
Signed-off-by: Bridge Wu <mingqiao.wu@gmail.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

drivers/mmc/host/pxamci.c

@@ -298,7 +298,7 @@ static irqreturn_t pxamci_irq(int irq, void *devid)
 	unsigned int ireg;
 	int handled = 0;
 
-	ireg = readl(host->base + MMC_I_REG);
+	ireg = readl(host->base + MMC_I_REG) & ~readl(host->base + MMC_I_MASK);
 
 	if (ireg) {
 		unsigned stat = readl(host->base + MMC_STAT);