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/arm/cpu/ixp/npe/miiphy.c b/arch/arm/cpu/ixp/npe/miiphy.c
index b208c51..4b0201a 100644
--- a/arch/arm/cpu/ixp/npe/miiphy.c
+++ b/arch/arm/cpu/ixp/npe/miiphy.c
@@ -100,7 +100,7 @@
 }
 
 
-int npe_miiphy_read (char *devname, unsigned char addr,
+int npe_miiphy_read (const char *devname, unsigned char addr,
 		     unsigned char reg, unsigned short *value)
 {
 	u16 val;
@@ -112,7 +112,7 @@
 }				/* phy_read */
 
 
-int npe_miiphy_write (char *devname, unsigned char addr,
+int npe_miiphy_write (const char *devname, unsigned char addr,
 		      unsigned char reg, unsigned short value)
 {
 	ixEthAccMiiWriteRtn(addr, reg, value);