config: Switch CONFIG_PREEMPT to CONFIG_PREEMPT_VOLUNTARY

See discussion here: #1216

Author: popcornmix

arch/arm/configs/bcm2709_defconfig

@@ -44,7 +44,7 @@ CONFIG_BCM2709_DT=y
 CONFIG_SMP=y
 CONFIG_HAVE_ARM_ARCH_TIMER=y
 CONFIG_VMSPLIT_2G=y
-CONFIG_PREEMPT=y
+CONFIG_PREEMPT_VOLUNTARY=y
 CONFIG_AEABI=y
 CONFIG_OABI_COMPAT=y
 CONFIG_CLEANCACHE=y
@@ -1230,7 +1230,6 @@ CONFIG_BOOT_PRINTK_DELAY=y
 CONFIG_DEBUG_MEMORY_INIT=y
 CONFIG_DETECT_HUNG_TASK=y
 CONFIG_TIMER_STATS=y
-# CONFIG_DEBUG_PREEMPT is not set
 CONFIG_IRQSOFF_TRACER=y
 CONFIG_SCHED_TRACER=y
 CONFIG_STACK_TRACER=y

arch/arm/configs/bcmrpi_defconfig

@@ -39,7 +39,7 @@ CONFIG_MAC_PARTITION=y
 CONFIG_CFQ_GROUP_IOSCHED=y
 CONFIG_ARCH_BCM2708=y
 CONFIG_BCM2708_DT=y
-CONFIG_PREEMPT=y
+CONFIG_PREEMPT_VOLUNTARY=y
 CONFIG_AEABI=y
 CONFIG_OABI_COMPAT=y
 CONFIG_CLEANCACHE=y
@@ -1223,7 +1223,6 @@ CONFIG_BOOT_PRINTK_DELAY=y
 CONFIG_DEBUG_MEMORY_INIT=y
 CONFIG_DETECT_HUNG_TASK=y
 CONFIG_TIMER_STATS=y
-# CONFIG_DEBUG_PREEMPT is not set
 CONFIG_LATENCYTOP=y
 CONFIG_IRQSOFF_TRACER=y
 CONFIG_SCHED_TRACER=y