pwm: constify pwm_ops structures

Declare pwm_ops structures as const as they are only stored in the ops
field of a pwm_chip structure. This field is of type const struct pwm_ops
*, so pwm_ops structures having this property can be declared as const.
Done using Coccinelle:

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

@ok1@
identifier r1.i;
position p;
struct pxa_pwm_chip pwm;
struct bfin_pwm_chip bwm;
struct vt8500_chip vp;
struct imx_chip icp;
@@
(
pwm.chip.ops=&i@p
|
bwm.chip.ops=&i@p
|
vp.chip.ops=&i@p
|
icp.chip.ops=&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 pwm_ops i;

File size details:

text data bss dec hex filename
1646 328 0 1974 7b6 drivers/pwm/pwm-imx.o
1742 224 0 1966 7ae drivers/pwm/pwm-imx.o

1941 296 0 2237 8bd drivers/pwm/pwm-pxa.o
2037 192 0 2229 8b5 drivers/pwm/pwm-pxa.o

1946 296 0 2242 8c2 drivers/pwm/pwm-vt8500.o
2050 192 0 2242 8c2 drivers/pwm/pwm-vt8500.o

The drivers/pwm/pwm-bfin.o file did not compile.

Signed-off-by: Bhumika Goyal <[e-mail]>
Signed-off-by: Thierry Reding <[e-mail]>

drivers/pwm/pwm-bfin.c

···
 	disable_gptimer(priv->pin);
 }
 
-static struct pwm_ops bfin_pwm_ops = {
+static const struct pwm_ops bfin_pwm_ops = {
 	.request = bfin_pwm_request,
 	.free = bfin_pwm_free,
 	.config = bfin_pwm_config,

drivers/pwm/pwm-imx.c

···
 	clk_disable_unprepare(imx->clk_per);
 }
 
-static struct pwm_ops imx_pwm_ops = {
+static const struct pwm_ops imx_pwm_ops = {
 	.enable = imx_pwm_enable,
 	.disable = imx_pwm_disable,
 	.config = imx_pwm_config,

drivers/pwm/pwm-pxa.c

···
 	clk_disable_unprepare(pc->clk);
 }
 
-static struct pwm_ops pxa_pwm_ops = {
+static const struct pwm_ops pxa_pwm_ops = {
 	.config = pxa_pwm_config,
 	.enable = pxa_pwm_enable,
 	.disable = pxa_pwm_disable,

drivers/pwm/pwm-vt8500.c

···
 	return 0;
 }
 
-static struct pwm_ops vt8500_pwm_ops = {
+static const struct pwm_ops vt8500_pwm_ops = {
 	.enable = vt8500_pwm_enable,
 	.disable = vt8500_pwm_disable,
 	.config = vt8500_pwm_config,