greybus: firmware.h: rename TFTF firmware filenames

Replace prefix "ara_" with prefix "gmp_" for TFTF firmware filenames.

Testing Done: compiled and flashed EVT2 (bootimage) and tested that
              "gmp_" prefixed tftf files are expected. Pushed one from
	      FDK and checked that it's properly loaded.
Signed-off-by: Joel Porquet <porquet_joel@projectara.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sandeep Patil <sspatil@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/firmware.h

@@ -12,7 +12,7 @@
 
 #include "greybus.h"
 
-#define FW_NAME_PREFIX	"ara_"
+#define FW_NAME_PREFIX	"gmp_"
 
 /* Length of the string in format: "FW_NAME_PREFIX""%08x_%08x_%08x_%08x_%s.tftf" */
 #define FW_NAME_LEN		56