x86 realmode: Adapt to x86emu/YABEL style return codes

realmode int handlers must return the same codes as the YABEL
int handlers now: 1 for "interrupt handled", 0 for "not handled"
(ie. error).

Change-Id: Idc01cf64e2c97150fc4643671a0bc4cca2ae6668
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Reviewed-on: http://review.coreboot.org/1890
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
13 files changed