ARM: OMAP2+: PRCM: create SoC-specific chip restart functions

Split omap_prcm_restart() from mach-omap2/prcm.c into SoC-specific
variants.  These functions need to be able to save the reboot reason
into the scratchpad RAM.  This implies a dependency on both the PRM
and SCM IP blocks, so they've been moved into their own file.  This
will eventually call functions in the PRM and SCM drivers, once those
are created.

Vaibhav Hiremath <hvaibhav@ti.com> identified an unused prototype in
the first version of this patch - now removed.  Tony Lindgren
<tony@atomide.com> noted a compile problem with some RMK Kconfigs;
resolved in this patch.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Vaibhav Hiremath <hvaibhav@ti.com>
Tested-by: Vaibhav Hiremath <hvaibhav@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/common.h b/arch/arm/mach-omap2/common.h
index ed21815..349d015 100644
--- a/arch/arm/mach-omap2/common.h
+++ b/arch/arm/mach-omap2/common.h
@@ -113,6 +113,30 @@
 int omap2_common_pm_late_init(void);
 void omap_prcm_restart(char, const char *);
 
+#if defined(CONFIG_SOC_OMAP2420) || defined(CONFIG_SOC_OMAP2430)
+void omap2xxx_restart(char mode, const char *cmd);
+#else
+static inline void omap2xxx_restart(char mode, const char *cmd)
+{
+}
+#endif
+
+#ifdef CONFIG_ARCH_OMAP3
+void omap3xxx_restart(char mode, const char *cmd);
+#else
+static inline void omap3xxx_restart(char mode, const char *cmd)
+{
+}
+#endif
+
+#if defined(CONFIG_ARCH_OMAP4) || defined(CONFIG_SOC_OMAP5)
+void omap44xx_restart(char mode, const char *cmd);
+#else
+static inline void omap44xx_restart(char mode, const char *cmd)
+{
+}
+#endif
+
 /* This gets called from mach-omap2/io.c, do not call this */
 void __init omap2_set_globals_tap(u32 class, void __iomem *tap);