arc: fix Z_ARCH_THREAD_STACK_MEMBER()

Unlike the others, this macro was not taking into
account minimum MPU region sizes by filtering through
STACK_SIZE_ALIGN().

Fixes: #15130

Signed-off-by: Andrew Boie <[email protected]>

Author: Andrew Boie

include/arch/arc/arch.h

@@ -105,7 +105,7 @@ extern "C" {
 #define Z_ARCH_THREAD_STACK_MEMBER(sym, size) \
 	struct _k_thread_stack_element \
 		__aligned(POW2_CEIL(STACK_SIZE_ALIGN(size))) \
-		sym[POW2_CEIL(size) + \
+		sym[POW2_CEIL(STACK_SIZE_ALIGN(size)) + \
 		+ STACK_GUARD_SIZE + CONFIG_PRIVILEGED_STACK_SIZE]
 
 #elif CONFIG_ARC_MPU_VER == 3