miiphy: constify device name

The driver name does not need to be writable, so constify it.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
diff --git a/arch/powerpc/cpu/mpc8220/fec.c b/arch/powerpc/cpu/mpc8220/fec.c
index 9a6d434..00879df 100644
--- a/arch/powerpc/cpu/mpc8220/fec.c
+++ b/arch/powerpc/cpu/mpc8220/fec.c
@@ -34,8 +34,8 @@
 	u8 head[16];		/* MAC header(6 + 6 + 2) + 2(aligned) */
 } NBUF;
 
-int fec8220_miiphy_read (char *devname, u8 phyAddr, u8 regAddr, u16 * retVal);
-int fec8220_miiphy_write (char *devname, u8 phyAddr, u8 regAddr, u16 data);
+int fec8220_miiphy_read (const char *devname, u8 phyAddr, u8 regAddr, u16 *retVal);
+int fec8220_miiphy_write (const char *devname, u8 phyAddr, u8 regAddr, u16 data);
 
 /********************************************************************/
 #ifdef DEBUG
@@ -881,7 +881,7 @@
 
 /* MII-interface related functions */
 /********************************************************************/
-int fec8220_miiphy_read (char *devname, u8 phyAddr, u8 regAddr, u16 * retVal)
+int fec8220_miiphy_read (const char *devname, u8 phyAddr, u8 regAddr, u16 *retVal)
 {
 	ethernet_regs *eth = (ethernet_regs *) MMAP_FEC1;
 	u32 reg;		/* convenient holder for the PHY register */
@@ -925,7 +925,7 @@
 }
 
 /********************************************************************/
-int fec8220_miiphy_write (char *devname, u8 phyAddr, u8 regAddr, u16 data)
+int fec8220_miiphy_write(const char *devname, u8 phyAddr, u8 regAddr, u16 data)
 {
 	ethernet_regs *eth = (ethernet_regs *) MMAP_FEC1;
 	u32 reg;		/* convenient holder for the PHY register */