PCI: ls-gen4: Make struct mobiveil_rp_ops constant

The struct mobiveil_rp_ops is not modified in this driver.

Thus, make this struct constant, which also moves data to a read-only
section decreasing object size and also improving overall security.

On a x86_64, with allmodconfig, as an example:

Before:
======
   text	   data	    bss	    dec	    hex	filename
   4446	    336	     32	   4814	   12ce	drivers/pci/controller/mobiveil/pcie-layerscape-gen4.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
   4454	    328	     32	   4814	   12ce	drivers/pci/controller/mobiveil/pcie-layerscape-gen4.o

[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/189fd881cc8fd80220e74e91820e12cf3a5be114.1719260294.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

Author: tititiou36

drivers/pci/controller/mobiveil/pcie-layerscape-gen4.c

@@ -190,7 +190,7 @@ static void ls_g4_pcie_reset(struct work_struct *work)
 	ls_g4_pcie_enable_interrupt(pcie);
 }
 
-static struct mobiveil_rp_ops ls_g4_pcie_rp_ops = {
+static const struct mobiveil_rp_ops ls_g4_pcie_rp_ops = {
 	.interrupt_init = ls_g4_pcie_interrupt_init,
 };
 

drivers/pci/controller/mobiveil/pcie-mobiveil.h

@@ -151,7 +151,7 @@ struct mobiveil_rp_ops {
 struct mobiveil_root_port {
 	void __iomem *config_axi_slave_base;	/* endpoint config base */
 	struct resource *ob_io_res;
-	struct mobiveil_rp_ops *ops;
+	const struct mobiveil_rp_ops *ops;
 	int irq;
 	raw_spinlock_t intx_mask_lock;
 	struct irq_domain *intx_domain;