[ARM] pxa: corgibl_limit_intensity build errors

If CONFIG_BACKLIGHT_CORGI is not selected, then corgibl_limit_intensity()
is not present.  However, both corgi_pm.c and sharp_pm.c reference this
symbol, resulting in a link error.

Wrap the references with the relevant ifdefs, and avoid the resulting
NULL pointer dereference by making the code in sharpsl_pm.c also
conditional on the config symbol.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/common/sharpsl_pm.c

@@ -157,6 +157,7 @@ static void sharpsl_battery_thread(struct work_struct *private_)
 	dev_dbg(sharpsl_pm.dev, "Battery: voltage: %d, status: %d, percentage: %d, time: %ld\n", voltage,
 			sharpsl_pm.battstat.mainbat_status, sharpsl_pm.battstat.mainbat_percent, jiffies);
 
+#ifdef CONFIG_BACKLIGHT_CORGI
 	/* If battery is low. limit backlight intensity to save power. */
 	if ((sharpsl_pm.battstat.ac_status != APM_AC_ONLINE)
 			&& ((sharpsl_pm.battstat.mainbat_status == APM_BATTERY_STATUS_LOW) ||
@@ -169,6 +170,7 @@ static void sharpsl_battery_thread(struct work_struct *private_)
 		sharpsl_pm.machinfo->backlight_limit(0);
 		sharpsl_pm.flags &= ~SHARPSL_BL_LIMIT;
 	}
+#endif
 
 	/* Suspend if critical battery level */
 	if ((sharpsl_pm.battstat.ac_status != APM_AC_ONLINE)

arch/arm/mach-pxa/corgi_pm.c

@@ -204,7 +204,9 @@ static struct sharpsl_charger_machinfo corgi_pm_machinfo = {
 	.read_devdata    = corgipm_read_devdata,
 	.charger_wakeup  = corgi_charger_wakeup,
 	.should_wakeup   = corgi_should_wakeup,
+#ifdef CONFIG_BACKLIGHT_CORGI
 	.backlight_limit = corgibl_limit_intensity,
+#endif
 	.charge_on_volt	  = SHARPSL_CHARGE_ON_VOLT,
 	.charge_on_temp	  = SHARPSL_CHARGE_ON_TEMP,
 	.charge_acin_high = SHARPSL_CHARGE_ON_ACIN_HIGH,

arch/arm/mach-pxa/spitz_pm.c

@@ -207,7 +207,9 @@ struct sharpsl_charger_machinfo spitz_pm_machinfo = {
 	.read_devdata     = spitzpm_read_devdata,
 	.charger_wakeup   = spitz_charger_wakeup,
 	.should_wakeup    = spitz_should_wakeup,
+#ifdef CONFIG_BACKLIGHT_CORGI
         .backlight_limit  = corgibl_limit_intensity,
+#endif
 	.charge_on_volt	  = SHARPSL_CHARGE_ON_VOLT,
 	.charge_on_temp	  = SHARPSL_CHARGE_ON_TEMP,
 	.charge_acin_high = SHARPSL_CHARGE_ON_ACIN_HIGH,