dm: pci: Update a few more interfaces for const udevice *

Tidy up a few places where const * should be used.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/pci.h b/include/pci.h
index 40e3c3f..50ca249 100644
--- a/include/pci.h
+++ b/include/pci.h
@@ -924,7 +924,7 @@
  * @dev:	Device to check
  * @return bus/device/function value (see PCI_BDF())
  */
-pci_dev_t dm_pci_get_bdf(struct udevice *dev);
+pci_dev_t dm_pci_get_bdf(const struct udevice *dev);
 
 /**
  * pci_bind_bus_devices() - scan a PCI bus and bind devices
@@ -1067,7 +1067,7 @@
  * @size:	Access size
  * @return 0 if OK, -ve on error
  */
-int pci_bus_read_config(struct udevice *bus, pci_dev_t bdf, int offset,
+int pci_bus_read_config(const struct udevice *bus, pci_dev_t bdf, int offset,
 			unsigned long *valuep, enum pci_size_t size);
 
 /**
@@ -1102,12 +1102,12 @@
  * Driver model PCI config access functions. Use these in preference to others
  * when you have a valid device
  */
-int dm_pci_read_config(struct udevice *dev, int offset, unsigned long *valuep,
-		       enum pci_size_t size);
+int dm_pci_read_config(const struct udevice *dev, int offset,
+		       unsigned long *valuep, enum pci_size_t size);
 
-int dm_pci_read_config8(struct udevice *dev, int offset, u8 *valuep);
-int dm_pci_read_config16(struct udevice *dev, int offset, u16 *valuep);
-int dm_pci_read_config32(struct udevice *dev, int offset, u32 *valuep);
+int dm_pci_read_config8(const struct udevice *dev, int offset, u8 *valuep);
+int dm_pci_read_config16(const struct udevice *dev, int offset, u16 *valuep);
+int dm_pci_read_config32(const struct udevice *dev, int offset, u32 *valuep);
 
 int dm_pci_write_config(struct udevice *dev, int offset, unsigned long value,
 			enum pci_size_t size);
@@ -1313,7 +1313,7 @@
  * @barnum:	Bar number to read (numbered from 0)
  * @return: value of BAR
  */
-u32 dm_pci_read_bar32(struct udevice *dev, int barnum);
+u32 dm_pci_read_bar32(const struct udevice *dev, int barnum);
 
 /**
  * dm_pci_bus_to_phys() - convert a PCI bus address to a physical address