ARM: OMAP2+: PRM: provide generic API for system reset

This patch combines the various prm_warm_reset calls under a common
API prm_reset_system, and adds the SoC specific implementation under
prm_ll_data.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/prm2xxx.h

@@ -124,7 +124,6 @@
 extern int omap2xxx_clkdm_sleep(struct clockdomain *clkdm);
 extern int omap2xxx_clkdm_wakeup(struct clockdomain *clkdm);
 
-extern void omap2xxx_prm_dpll_reset(void);
 void omap2xxx_prm_clear_mod_irqs(s16 module, u8 regs, u32 wkst_mask);
 
 extern int __init omap2xxx_prm_init(void);