Use fbgemm_fml_flags and add fbgemm_sve guard

[cyyever]

Add a missing part in #4942 .
I also fix another aarch64 issue on PyTorch CI:

/var/lib/jenkins/workspace/third_party/fbgemm/include/fbgemm/./Utils.h:26:10: fatal error: arm_neon_sve_bridge.h: No such file or directory
   26 | #include <arm_neon_sve_bridge.h> // @manual
      |          ^~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

ARM documentation says:

SVE and SVE2 feature paths in libaom, libvpx, and x265 require the intrinsics declared in arm_neon_sve_bridge.h. This header file is available in the following releases:

Clang 17 and later.
GCC 14 and later.

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@q10 has imported this pull request. If you are a Meta employee, you can view this in D83578552.

[q10]

Looks like we're running into

Error: unknown architecture `-march=armv8.2-a+fp16fml'

[cyyever]

@q10 fixed

[cyyever]

@q10 Unrelated failure

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@q10 merged this pull request in 56ecc59.