Default fallback macros for BSWAP and SYNC
In case no processor specific definitions exist use bswap() and empty macro for SYNC.
vme_rcc and rcc_timestamp are the two packages that do not compile on ARM aarch64 architecture due to processor specific assembler instructions and no generic fallback. This defines the BSWAP and SYNC macro in such a case (I don't think we need to optimize these for this architecture now...).
@joos , please merge and tag for nightly, if ok. I will take care to include it into our special ARM builds.