When the compiler is not capable/does not accept -msse4.1 while the target
has the instruction set we'll blow up as _mesa_streaming_load_memcpy is
going to be undefined.

To make sure that never happens, wrap the runtime cpu check+caller in an
ifdef thus do not compile that hunk of the code.

Fix the android build by enabling the optimisation and adding the define
where applicable.

v2: autoconf conditionals end with "fi" rather than endif.
v3: Wrap the definition and call to intel_miptree_{un,}map_movntdqa in
if defined(USE_SSE41). Spotted by Matt.

Cc: Matt Turner <mattst88@gmail.com>
Cc: Adrian Negreanu <adrian.m.negreanu@intel.com>
Cc: "10.1 10.2" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>