PCI: mobiveil: Fix INTx interrupt clearing in mobiveil_pcie_isr()

The current INTx handling function clears all interrupts after
handling the first pending; this can potentially cause missing INTx
detection. Fix the code to clear only the handled INTx IRQ.

Fixes: 9af6bcb ("PCI: mobiveil: Add Mobiveil PCIe Host Bridge IP driver")
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Reviewed-by: Subrahmanya Lingappa <l.subrahmanya@mobiveil.co.in>
Acked-by: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>
Tested-by: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>

drivers/pci/controller/pcie-mobiveil.c

@@ -371,9 +371,8 @@ static void mobiveil_pcie_isr(struct irq_desc *desc)
 					dev_err_ratelimited(dev, "unexpected IRQ, INT%d\n",
 							    bit);
 
-				/* clear interrupt */
-				csr_writel(pcie,
-					   shifted_status << PAB_INTX_START,
+				/* clear interrupt handled */
+				csr_writel(pcie, 1 << (PAB_INTX_START + bit),
 					   PAB_INTP_AMBA_MISC_STAT);
 			}