mfd: rohm-bd71828: Constify some structures

Several structures are not modified in this driver. Constifying them moves
some data to a read-only section, so increases overall security, especially
when the structure holds some function pointers. This is the case for
'gpio_keys_platform_data' and 'mfd_cell'.

On a x86_64, with allmodconfig:
Before:
======
   text	   data	    bss	    dec	    hex	filename
  18321	  13952	    192	  32465	   7ed1	drivers/mfd/rohm-bd71828.o

After:
=====
   text	   data	    bss	    dec	    hex	filename
  22897	   9376	    192	  32465	   7ed1	drivers/mfd/rohm-bd71828.o

Signed-off-by: Christophe JAILLET <[email protected]>
Reviewed-by: Matti Vaittinen <[email protected]>
Link: https://lore.kernel.org/r/037e28e587ae899da9acdb45c606d75ec61f858b.1750501700.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Lee Jones <[email protected]>

Author: tititiou36

drivers/mfd/rohm-bd71828.c

@@ -25,7 +25,7 @@ static struct gpio_keys_button button = {
 	.type = EV_KEY,
 };
 
-static struct gpio_keys_platform_data bd71828_powerkey_data = {
+static const struct gpio_keys_platform_data bd71828_powerkey_data = {
 	.buttons = &button,
 	.nbuttons = 1,
 	.name = "bd71828-pwrkey",
@@ -43,7 +43,7 @@ static const struct resource bd71828_rtc_irqs[] = {
 	DEFINE_RES_IRQ_NAMED(BD71828_INT_RTC2, "bd70528-rtc-alm-2"),
 };
 
-static struct resource bd71815_power_irqs[] = {
+static const struct resource bd71815_power_irqs[] = {
 	DEFINE_RES_IRQ_NAMED(BD71815_INT_DCIN_RMV, "bd71815-dcin-rmv"),
 	DEFINE_RES_IRQ_NAMED(BD71815_INT_CLPS_OUT, "bd71815-clps-out"),
 	DEFINE_RES_IRQ_NAMED(BD71815_INT_CLPS_IN, "bd71815-clps-in"),
@@ -93,7 +93,7 @@ static struct resource bd71815_power_irqs[] = {
 	DEFINE_RES_IRQ_NAMED(BD71815_INT_TEMP_BAT_HI_DET, "bd71815-bat-hi-det"),
 };
 
-static struct mfd_cell bd71815_mfd_cells[] = {
+static const struct mfd_cell bd71815_mfd_cells[] = {
 	{ .name = "bd71815-pmic", },
 	{ .name = "bd71815-clk", },
 	{ .name = "bd71815-gpo", },
@@ -109,7 +109,7 @@ static struct mfd_cell bd71815_mfd_cells[] = {
 	},
 };
 
-static struct mfd_cell bd71828_mfd_cells[] = {
+static const struct mfd_cell bd71828_mfd_cells[] = {
 	{ .name = "bd71828-pmic", },
 	{ .name = "bd71828-gpio", },
 	{ .name = "bd71828-led", .of_compatible = "rohm,bd71828-leds" },
@@ -493,7 +493,7 @@ static int bd71828_i2c_probe(struct i2c_client *i2c)
 	const struct regmap_config *regmap_config;
 	const struct regmap_irq_chip *irqchip;
 	unsigned int chip_type;
-	struct mfd_cell *mfd;
+	const struct mfd_cell *mfd;
 	int cells;
 	int button_irq;
 	int clkmode_reg;