arch: arc: adjust privileged stack size of arc to 384 bytes

Considering the case of call of printk, interrupt and
other cases, adjust the privileged stack size of arc to
384 bytes to avoid the the overflow of privileged stack.

Signed-off-by: Wayne Ren <[email protected]>

Author: Wayne Ren

arch/Kconfig

@@ -82,6 +82,7 @@ config USERSPACE
 config PRIVILEGED_STACK_SIZE
 	int "Size of privileged stack"
 	default 256
+	default 384 if ARC
 	depends on ARCH_HAS_USERSPACE
 	help
 	  This option sets the privileged stack region size that will be used