PCI: tegra: make const array err_msg static

Don't populate the array err_msg on the stack but instead make it
static. Makes the object code smaller by 64 bytes.

While at it, add a missing const, as reported by checkpatch.

Compiled with gcc 11.0.1

Before:
$ size drivers/pci/controller/pci-tegra.o
   text	   data	    bss	    dec	    hex	filename
  25623	   2844	     32	  28499	   6f53	drivers/pci/controller/pci-tegra.o

After:
$ size drivers/pci/controller/pci-tegra.o
   text	   data	    bss	    dec	    hex	filename
  25559	   2844	     32	  28435	   6f13	drivers/pci/controller/pci-tegra.o

Link: https://lore.kernel.org/r/5f3f35296b944b94546cc7d1e9cc6186484620d8.1620148539.git.christophe.jaillet@wanadoo.frSigned-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NVidya Sagar <vidyas@nvidia.com>

drivers/pci/controller/pci-tegra.c

@@ -759,7 +759,7 @@ static int tegra_pcie_map_irq(const struct pci_dev *pdev, u8 slot, u8 pin)
 
 static irqreturn_t tegra_pcie_isr(int irq, void *arg)
 {
-	const char *err_msg[] = {
+	static const char * const err_msg[] = {
 		"Unknown",
 		"AXI slave error",
 		"AXI decode error",