sam: added {upload.verify} option in platform.txt

Author: cmaglie

platform.txt

@@ -102,5 +102,6 @@ tools.bossac.cmd.windows=bossac.exe
 
 tools.bossac.upload.params.verbose=-i -d
 tools.bossac.upload.params.quiet=
-tools.bossac.upload.pattern="{path}/{cmd}" {upload.verbose} --port={serial.port.file} -U {upload.native_usb} -e -w -v -b "{build.path}/{build.project_name}.bin" -R
+tools.bossac.upload.params.verify=-v
+tools.bossac.upload.pattern="{path}/{cmd}" {upload.verbose} --port={serial.port.file} -U {upload.native_usb} -e -w {upload.verify} -b "{build.path}/{build.project_name}.bin" -R