meson: Fix build error with MSVC caused by ARCH_X86_64 define
ARCH_X86_64 define will enable GCC specific code path in dv_types.h while building dv plugin.
Fixes: cerbero#280 (closed)
cc: @vivia
ARCH_X86_64 define will enable GCC specific code path in dv_types.h while building dv plugin.
Fixes: cerbero#280 (closed)
cc: @vivia