x86: apic interrupts - move assignments to irqinit_32.c, v2

64bit mode APIC interrupt handlers are set within irqinit_64.c.
Lets do tha same for 32bit mode which would help in furter code merging.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>