arch: enable ARCH_KERNEL_STACK support in protected builds

Expand ARCH_KERNEL_STACK configuration to support both BUILD_KERNEL and
BUILD_PROTECTED modes. Change Kconfig dependency from "depends on BUILD_KERNEL"
to "depends on BUILD_KERNEL || BUILD_PROTECTED". Update pthread_create.c to
remove redundant BUILD_KERNEL check when allocating kernel stacks with
CONFIG_ARCH_KERNEL_STACK enabled. Enables protected builds to use separate
kernel and user stacks for processes.

Signed-off-by: hujun5 <hujun5@xiaomi.com>

arch/Kconfig

@@ -907,7 +907,7 @@ endif # ARCH_STACK_DYNAMIC
 config ARCH_KERNEL_STACK
 	bool "Kernel process stack"
 	default LIBC_EXECFUNCS
-	depends on BUILD_KERNEL
+	depends on BUILD_KERNEL || BUILD_PROTECTED
 	---help---
 		It this option is selected, then every user process will have two
 		stacks:  A large, potentially dynamically sized user stack and small

sched/pthread/pthread_create.c

@@ -273,8 +273,7 @@ int nx_pthread_create(pthread_trampoline_t trampoline, FAR pthread_t *thread,
       goto errout_with_tcb;
     }
 
-#if defined(CONFIG_ARCH_ADDRENV) && \
-    defined(CONFIG_BUILD_KERNEL) && defined(CONFIG_ARCH_KERNEL_STACK)
+#if defined(CONFIG_ARCH_ADDRENV) && defined(CONFIG_ARCH_KERNEL_STACK)
   /* Allocate the kernel stack */
 
   ret = up_addrenv_kstackalloc(ptcb);