releasetools: Add radio images to fastboot packages
releasetools: Add radio images to fastboot packages

Fastboot packages should include radio images, if they exist. Also
generate a flash-radio.sh file if a filesmap file exists to indicate
the partition that a radio image should be flashed to.

Change-Id: Ic3392cc76407408b98aad00f36f4dfa3b9be176b

fallouttester/platform_manifest,ND-3500/platform_manifest,see4ri/lolili,pranav01/platform_manifest,knone1/platform_manifest,Hybrid-Power/startsync,hagar006/platform_manifest,RR-msm7x30/platform_manifest