graphics/vapoursynth-fmtconv: limit to x86 and arm
Based on src/fstb/def.h:
#if defined (__i386__) || defined (_M_IX86) || defined (_X86_) || defined (_M_X64) || defined (__x86_64__) || defined (__INTEL__) #define fstb_ARCHI fstb_ARCHI_X86 #elif defined (__arm__) || defined (__arm) || defined (__arm64__) || defined (__arm64) || defined (_M_ARM) || defined (__aarch64__) #define fstb_ARCHI fstb_ARCHI_ARM #else #error #endif
(cherry picked from commit 646ee61254f0de8b6d3541f19d326ac00078fb2d)