Use px4_config.h instead of nuttx/config.h

Modified code to use OS independent header file for config settings.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

src/systemcmds/mtd/24xxxx_mtd.c

@@ -50,7 +50,7 @@
  * Included Files
  ************************************************************************************/
 
-#include <nuttx/config.h>
+#include <px4_config.h>
 
 #include <sys/types.h>
 #include <stdint.h>

src/systemcmds/mtd/mtd.c

@@ -39,7 +39,7 @@
  * @author Lorenz Meier <lm@inf.ethz.ch>
  */
 
-#include <nuttx/config.h>
+#include <px4_config.h>
 
 #include <stdio.h>
 #include <stdlib.h>