ARM: OMAP2+: SmartReflex: add omap_sr_pdata definition

The omap_sr_pdata is not declared but is exported, so add a
define for it to fix the following warning:

arch/arm/mach-omap2/pdata-quirks.c:609:36: warning: symbol 'omap_sr_pdata' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/linux/power/smartreflex.h

@@ -293,6 +293,9 @@ struct omap_sr_data {
 	struct voltagedomain		*voltdm;
 };
 
+
+extern struct omap_sr_data omap_sr_pdata[OMAP_SR_NR];
+
 #ifdef CONFIG_POWER_AVS_OMAP
 
 /* Smartreflex module enable/disable interface */