Tweak default x86 target arch variant.
Tweak default x86 target arch variant.

Simply set the arch variant for sim-eng to be "x86".

xorware/android_build,fallouttester/platform_manifest,see4ri/lolili,Hybrid-Power/startsync,RR-msm7x30/platform_manifest,pranav01/platform_manifest,hagar006/platform_manifest,knone1/platform_manifest,xorware/android_build,xorware/android_build,xorware/android_build,ND-3500/platform_manifest,xorware/android_build