x86: implement hw-based oops for both variants

We use a fixed value of 32 as the way interrupts/exceptions
are setup in x86_64's locore.S do not lend themselves to
Kconfig configuration of the vector to use.

HW-based kernel oops is now permanently on, there's no reason
to make it optional that I can see.

Default vectors for IPI and irq offload adjusted to not
collide.

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