arm: use gen_isr_tables mechanism for interrupts

This replaces the hard-coded vector table, as well as the
software ISR table created by the linker. Now both are generated
in build via script.

Issue: ZEP-1038, ZEP-1165
Change-Id: Ie6faaf8f7ea3a7a25ecb542f6cf7740836ad7da3
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>