drivers: remoteproc: constify rproc_ops structures

Declare rproc_ops structures as const as they are only passed as an
argument to the function rproc_alloc. This argument is of type const, so
rproc_ops structures having this property can be declared const too.
Done using Coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct rproc_ops i@p = {...};

@ok1@
identifier r1.i;
position p;
@@
rproc_alloc(...,&i@p,...)

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct rproc_ops i;

File size details:

Size of the file remoteproc/da8xx_remoteproc.o remains the same before and
after applying the changes.

   text	   data	    bss	    dec	    hex	filename
   1312	    100	      4	   1416	    588 remoteproc/da8xx_remoteproc.o
   1312	    100	      4	   1416	    588 remoteproc/da8xx_remoteproc.o

    970	    240	      0	   1210	    4ba remoteproc/omap_remoteproc.o
   1002	    192	      0	   1194	    4aa remoteproc/omap_remoteproc.o

   1901	    240	      0	   2141	    85d remoteproc/st_remoteproc.o
   1933	    192	      0	   2125	    84d remoteproc/st_remoteproc.o

   1288	     96	      0	   1384	    568 remoteproc/st_slim_rproc.o
   1320	     64	      0	   1384	    568 remoteproc/st_slim_rproc.o

   2121	    240	      0	   2361	    939 remoteproc/wkup_m3_rproc.o
   2161	    192	      0	   2353	    931 remoteproc/wkup_m3_rproc.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
diff --git a/drivers/remoteproc/st_slim_rproc.c b/drivers/remoteproc/st_slim_rproc.c
index 507716c..6cfd862 100644
--- a/drivers/remoteproc/st_slim_rproc.c
+++ b/drivers/remoteproc/st_slim_rproc.c
@@ -200,7 +200,7 @@
 	return va;
 }
 
-static struct rproc_ops slim_rproc_ops = {
+static const struct rproc_ops slim_rproc_ops = {
 	.start		= slim_rproc_start,
 	.stop		= slim_rproc_stop,
 	.da_to_va       = slim_rproc_da_to_va,