gitignore: Ignore sptool and doimage binaries

Change-Id: I119b85179f68148e128cc194f11d2cccb1e33d6d
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

.gitignore

@@ -21,10 +21,12 @@ tools/cert_create/src/*.o
 tools/cert_create/src/**/*.o
 tools/cert_create/cert_create
 tools/cert_create/cert_create.exe
-tools/doimage/doimage
+tools/marvell/doimage/doimage
 tools/stm32image/*.o
 tools/stm32image/stm32image
 tools/stm32image/stm32image.exe
+tools/sptool/sptool
+tools/sptool/sptool.exe
 
 # GNU GLOBAL files
 GPATH