Move prototype of board_power_off() to include/nuttx/board.h where it belongs

arch/arm/src/calypso/calypso_power.c

@@ -1,18 +1,39 @@
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
 #include <stdio.h>
+
+#include <nuttx/board.h>
 #include <nuttx/spi/spi.h>
 
-int board_power_off(void)
+/****************************************************************************
+ * Name: board_power_off
+ *
+ * Description:
+ *   Power off the board.
+ *
+ *   If this function returns, then it was not possible to power-off the
+ *   board due to some other constraints.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void board_power_off(void)
 {
-	uint16_t tx;
-	struct spi_dev_s *spi = up_spiinitialize(0);
+  uint16_t tx;
+  struct spi_dev_s *spi = up_spiinitialize(0);
 
-	SPI_SETBITS(spi, 16);
+  SPI_SETBITS(spi, 16);
 
-	tx = (1 << 6) | (1 << 1);
-	SPI_SNDBLOCK(spi, &tx, 1);
+  tx = (1 << 6) | (1 << 1);
+  SPI_SNDBLOCK(spi, &tx, 1);
 
-	tx = (1 << 6) | (30 << 1);
-	SPI_SNDBLOCK(spi, &tx, 1);
-
-	return 0;
+  tx = (1 << 6) | (30 << 1);
+  SPI_SNDBLOCK(spi, &tx, 1);
 }

include/nuttx/board.h

@@ -272,6 +272,26 @@ FAR struct fb_vtable_s *board_graphics_setup(unsigned int devno);
 int board_ioctl(unsigned int cmd, uintptr_t arg);
 #endif
 
+/****************************************************************************
+ * Name: board_power_off
+ *
+ * Description:
+ *   Power off the board.  This function may or may not be supported by a
+ *   particular board architecture.
+ *
+ *   If this function returns, then it was not possible to power-off the
+ *   board due to some constraints.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void board_power_off(void);
+
 /****************************************************************************
  * Name: board_lcd_initialize, board_lcd_getdev, board_lcd_uninitialize
  *