move msi-related functionality to generic isrm

move msi-related functionality to generic isrm

* msi-related functionality are now part of generic isrm, as message
  based interrupt are actually de facto part of modern interrupt
  infrastructure.
* move bindirq and bindiv to x86-specific extension of isrm.
* ldelf will check the architecture before proceed to read anything
  other than elf-header.
* other minor tweaks