Created new directories to hold SPI-related files

configs/fire-stm32v2/src/up_enc28j60.c

@@ -55,7 +55,7 @@
 #include <stdio.h>
 #include <debug.h>
 
-#include <nuttx/spi.h>
+#include <nuttx/spi/spi.h>
 #include <nuttx/net/enc28j60.h>
 
 #include <arch/board/board.h>

configs/fire-stm32v2/src/up_spi.c

@@ -44,7 +44,7 @@
 #include <stdbool.h>
 #include <debug.h>
 
-#include <nuttx/spi.h>
+#include <nuttx/spi/spi.h>
 #include <arch/board/board.h>
 
 #include "up_arch.h"
@@ -139,7 +139,7 @@ void weak_function stm32_spiinitialize(void)
  *   The external functions, stm32_spi1/2/3select and stm32_spi1/2/3status must be
  *   provided by board-specific logic.  They are implementations of the select
  *   and status methods of the SPI interface defined by struct spi_ops_s (see
- *   include/nuttx/spi.h). All other methods (including up_spiinitialize())
+ *   include/nuttx/spi/spi.h). All other methods (including up_spiinitialize())
  *   are provided by common STM32 logic.  To use this common SPI logic on your
  *   board:
  *

configs/fire-stm32v2/src/up_w25.c

@@ -48,7 +48,7 @@
 #include <debug.h>
 
 #ifdef CONFIG_STM32_SPI1
-#  include <nuttx/spi.h>
+#  include <nuttx/spi/spi.h>
 #  include <nuttx/mtd.h>
 #  include <nuttx/fs/nxffs.h>
 #endif