Merge pull request #708 from PX4/stack_reduce

Reduce excessive stack sizes on main OS stacks.

nuttx-configs/px4fmu-v1/nsh/defconfig

@@ -417,7 +417,7 @@ CONFIG_PREALLOC_TIMERS=50
 #
 # Stack and heap information
 #
-CONFIG_IDLETHREAD_STACKSIZE=6000
+CONFIG_IDLETHREAD_STACKSIZE=4096
 CONFIG_USERMAIN_STACKSIZE=4096
 CONFIG_PTHREAD_STACK_MIN=512
 CONFIG_PTHREAD_STACK_DEFAULT=2048
@@ -720,11 +720,11 @@ CONFIG_SCHED_WORKQUEUE=y
 CONFIG_SCHED_HPWORK=y
 CONFIG_SCHED_WORKPRIORITY=192
 CONFIG_SCHED_WORKPERIOD=5000
-CONFIG_SCHED_WORKSTACKSIZE=4000
+CONFIG_SCHED_WORKSTACKSIZE=2048
 CONFIG_SCHED_LPWORK=y
 CONFIG_SCHED_LPWORKPRIORITY=50
 CONFIG_SCHED_LPWORKPERIOD=50000
-CONFIG_SCHED_LPWORKSTACKSIZE=4000
+CONFIG_SCHED_LPWORKSTACKSIZE=2048
 # CONFIG_LIB_KBDCODEC is not set
 # CONFIG_LIB_SLCDCODEC is not set