dvb frontends: treat firmware data as const

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/media/dvb/frontends/tda1004x.c b/drivers/media/dvb/frontends/tda1004x.c
index a0d6386..1465ff7 100644
--- a/drivers/media/dvb/frontends/tda1004x.c
+++ b/drivers/media/dvb/frontends/tda1004x.c
@@ -317,7 +317,7 @@
 }
 
 static int tda1004x_do_upload(struct tda1004x_state *state,
-			      unsigned char *mem, unsigned int len,
+			      const unsigned char *mem, unsigned int len,
 			      u8 dspCodeCounterReg, u8 dspCodeInReg)
 {
 	u8 buf[65];