[Mingw-cross-env-list] Need package: Physfs

[Safety0ff]

Parts that should to be looked at:
- No $(PKG)_UPDATE
- SHA1 taken from downloaded file (did not find online / reliable 
source) this is likely a no-no.
- Disabled building the test program included with the source as comment 
at top of file indicated uncertainty about whether it would work 
properly in non-unix environments (I didn't inspect/test further on this 
point).

Thanks,
-Safety0ff

physfs.mk
Description: Text document