Created new directories to hold SPI-related files

configs/stm32ldiscovery/src/stm32_spi.c

@@ -45,7 +45,7 @@
 #include <errno.h>
 #include <debug.h>
 
-#include <nuttx/spi.h>
+#include <nuttx/spi/spi.h>
 #include <arch/board/board.h>
 
 #include "up_arch.h"
@@ -109,7 +109,7 @@ 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:
  *
@@ -172,7 +172,7 @@ uint8_t stm32_spi3status(FAR struct spi_dev_s *dev, enum spi_dev_e devid)
  *   Set or clear the SH1101A A0 or SD1306 D/C n bit to select data (true)
  *   or command (false). This function must be provided by platform-specific
  *   logic. This is an implementation of the cmddata method of the SPI
- *   interface defined by struct spi_ops_s (see include/nuttx/spi.h).
+ *   interface defined by struct spi_ops_s (see include/nuttx/spi/spi.h).
  *
  * Input Parameters:
  *