OMAP3: cpuidle: change the power domains modes determination logic

The achievable power modes of the power domains in cpuidle
depends on the system wide 'enable_off_mode' knob in debugfs.
Upon changing enable_off_mode, do not change the C-states
'valid' field but instead dynamically restrict the power modes
when entering idle.

The C-states 'valid' field is just used to enable/disable some
C-states at init and shall not be changed later on.

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

arch/arm/mach-omap2/pm.h

@@ -78,10 +78,6 @@ extern u32 sleep_while_idle;
 #define sleep_while_idle 0
 #endif
 
-#if defined(CONFIG_CPU_IDLE)
-extern void omap3_cpuidle_update_states(u32, u32);
-#endif
-
 #if defined(CONFIG_PM_DEBUG) && defined(CONFIG_DEBUG_FS)
 extern void pm_dbg_update_time(struct powerdomain *pwrdm, int prev);
 extern int pm_dbg_regset_save(int reg_set);