maa: add global maa.h and maa.hpp and stop using /usr/include/maa/

* pkg-config now only sees maa.h & maa.hpp
* usage of maa/*.{h,hpp} is still allowed
* examples updated to use maa.{h,hpp}

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>

examples/spi_mcp4261.c

@@ -22,7 +22,7 @@
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#include "spi.h"
+#include "maa.h"
 #include <unistd.h>
 #include <stdint.h>