[POWERPC] 40x decrementer fixes

Allow generic_calibrate_decr to work for 40x platforms.  Given that the hardware
behavior is identical, this also changes the set_dec function to reload the PIT
on 40x to match the behavior 44x currently has.
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

arch/powerpc/kernel/time.c

@@ -866,7 +866,7 @@ void __init generic_calibrate_decr(void)
 				"(not found)\n");
 	}
 
-#ifdef CONFIG_BOOKE
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
 	/* Set the time base to zero */
 	mtspr(SPRN_TBWL, 0);
 	mtspr(SPRN_TBWU, 0);

include/asm-powerpc/time.h

@@ -174,7 +174,7 @@ static inline unsigned int get_dec(void)
 static inline void set_dec(int val)
 {
 #if defined(CONFIG_40x)
-	return;		/* Have to let it auto-reload */
+	mtspr(SPRN_PIT, val);
 #elif defined(CONFIG_8xx_CPU6)
 	set_dec_cpu6(val);
 #else