swr: [rasterizer] Do not define _mm256_storeu2_m128i with icc.

swr: [rasterizer] Do not define _mm256_storeu2_m128i with icc.

Fix build error with icc.

  CXX      libswrAVX_la-swr_clear.lo
icpc: command line warning #10006: ignoring unknown option '-Wdelete-non-virtual-dtor'
In file included from ./rasterizer/jitter/jit_api.h(31),
                 from swr_context.h(30),
                 from swr_clear.cpp(24):
./rasterizer/common/os.h(135): error: expected an identifier
  void _mm256_storeu2_m128i(__m128i *hi, __m128i *lo, __m256i a)
       ^

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Tim Rowley <timothy.o.rowley@intel.com>