ARM: OMAP2/3: PRM: add SoC reset functions (using the CORE DPLL method)

Add SoC reset functions into the PRM code.  These functions are based
on code from mach-omap2/prcm.c.  They reset the SoC using the CORE DPLL
reset method (as opposed to one of the other two or three chip reset
methods).

Adding them here will facilitate their removal from
arch/arm/mach-omap2/prcm.c.  (prcm.c is deprecated.)

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Tested-by: Vaibhav Hiremath <hvaibhav@ti.com>
diff --git a/arch/arm/mach-omap2/prm3xxx.h b/arch/arm/mach-omap2/prm3xxx.h
index a3c28a8..10cd41a 100644
--- a/arch/arm/mach-omap2/prm3xxx.h
+++ b/arch/arm/mach-omap2/prm3xxx.h
@@ -152,6 +152,8 @@
 extern void omap3xxx_prm_save_and_clear_irqen(u32 *saved_mask);
 extern void omap3xxx_prm_restore_irqen(u32 *saved_mask);
 
+extern void omap3xxx_prm_dpll3_reset(void);
+
 extern u32 omap3xxx_prm_get_reset_sources(void);
 
 #endif /* __ASSEMBLER */