The app-facing interface for configuring interrupts was never
formally defined, instead it was defined separately for each arch
in their respective arch-specific header files. Occasionally these
would go out of sync.
Now there is a single irq.h header which defines this interface.
To avoid runtime overhead, these map to _arch_* implementations of
each that must be defined in headers pulled in by arch/cpu.h.
Change-Id: I69afbeff31fd07f981b5b291f3c427296b00a4ef
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>