image_types_wic: add syslinux-native dependency conditional

image_types_wic: add syslinux-native dependency conditional

Add syslinux-native dependency only for IA host machines.

Able to build wic image successfully for below template which
uses legacy bios(syslinux):
https://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/scripts/lib/wic/canned-wks/directdisk-gpt.wks

[YOCTO #13276]

(From OE-Core rev: 7e2ee2b59319e1d2c185d65de47cc8f5c048dd03)

Signed-off-by: Naveen Saini <naveen.kumar.saini@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>