interrupts: new static IRQ API

The interrupt API has been redesigned:

- irq_connect() for dynamic interrupts renamed to irq_connect_dynamic().
  It will be used in situations where the new static irq_connect()
  won't work, i.e. the value of arguments can't be computed at build time
- a new API for static interrupts replaces irq_connect(). it is used
  exactly the same way as its dynamic counterpart. The old static irq
  macros will be removed
- Separate stub assembly files are no longer needed as the stubs are now
  generated inline with irq_connect()

ReST documentation updated for the changed API. Some detail about the
IDT in ROM added, and an oblique reference to the internal-only
_irq_handler_set() API removed; we don't talk about internal APIs in
the official documentation.

Change-Id: I280519993da0e0fe671eb537a876f67de33d3cd4
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>

arch/arm/core/irq_manage.c

@@ -136,7 +136,7 @@ void _irq_spurious(void *unused)
  *
  * @return the interrupt line number
  */
-int irq_connect(unsigned int irq,
+int irq_connect_dynamic(unsigned int irq,
 					    unsigned int prio,
 					    void (*isr)(void *arg),
 					    void *arg,