pcxhr: treat firmware data as const

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/sound/pci/pcxhr/pcxhr_core.c b/sound/pci/pcxhr/pcxhr_core.c
index 78aa81f..957e6af 100644
--- a/sound/pci/pcxhr/pcxhr_core.c
+++ b/sound/pci/pcxhr/pcxhr_core.c
@@ -269,7 +269,7 @@
 	unsigned int chipsc;
 	unsigned char data;
 	unsigned char mask;
-	unsigned char *image;
+	const unsigned char *image;
 
 	/* test first xilinx */
 	chipsc = PCXHR_INPL(mgr, PCXHR_PLX_CHIPSC);
@@ -316,7 +316,7 @@
 	int err;
 	unsigned int i;
 	unsigned int len;
-	unsigned char *data;
+	const unsigned char *data;
 	unsigned char dummy;
 	/* check the length of boot image */
 	snd_assert(dsp->size > 0, return -EINVAL);