microblaze: add const to of_device_id

struct of_device_id should normally be const.
Signed-off-by: NXiang wangx <wangxiang@cdjrlc.com>
Link: https://lore.kernel.org/r/20211212141248.7134-1-wangxiang@cdjrlc.comSigned-off-by: NMichal Simek <michal.simek@xilinx.com>

arch/microblaze/pci/xilinx_pci.c

@@ -27,7 +27,7 @@
 #define PCI_HOST_ENABLE_CMD (PCI_COMMAND_SERR | PCI_COMMAND_PARITY | \
 				PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY)
 
-static struct of_device_id xilinx_pci_match[] = {
+static const struct of_device_id xilinx_pci_match[] = {
 	{ .compatible = "xlnx,plbv46-pci-1.03.a", },
 	{}
 };