fix up_tls_info define for BUILD_KERNEL

Summary:
- In case of BUILD_KERNEL, NuttX uses USR mode sp and SVC mode sp.
- The kernel runs on SVC mode sp.
- While the kernel is running, up_getsp() cannot get the TLS address.
- The kernel requires tls_get_info() function.
- For the user land, up_getsp() can be used.
- tls_getinfo.c is always compiled and tls_get_info() function is
  filtered by macros in the tls_getinfo.c.

Impact:
BUILD_KERNEL

Testing:
test program on custom Cortex-A9 board (BUILD_KERNEL)
ostest on sabre-6quad:smp (QEMU, BUILD_FLAT)

Signed-off-by: Oki Minabe <minabe.oki@gmail.com>

include/nuttx/arch.h

@@ -1780,7 +1780,7 @@ int up_timer_start(FAR const struct timespec *ts);
  */
 
 #ifndef up_tls_info
-#  ifdef CONFIG_TLS_ALIGNED
+#  if defined(CONFIG_TLS_ALIGNED) && !defined(__KERNEL__)
 #    define up_tls_info() TLS_INFO((uintptr_t)up_getsp())
 #  else
 #    define up_tls_info() tls_get_info()

include/nuttx/tls.h

@@ -378,7 +378,7 @@ uintptr_t task_tls_get_value(int tlsindex);
  *
  ****************************************************************************/
 
-#ifndef CONFIG_TLS_ALIGNED
+#if !defined(CONFIG_TLS_ALIGNED) || defined(__KERNEL__)
 FAR struct tls_info_s *tls_get_info(void);
 #endif