eal/arm: fix clang build of native target
eal/arm: fix clang build of native target

When doing Clang build with '-mcpu=native' on N1 platform, build failed
with:
../lib/librte_eal/arm/include/rte_atomic_64.h:76:39:
	error: instruction requires: lse
__ATOMIC128_CAS_OP(__cas_128_release, "caspl")

This is because native detection for Neoverse N1 was added in Clang-11.
Prior version of Clang's assembler doesn't know LSE support on hardware.
Fixed this for Clang earlier than version 11 by specifying architecture
for assembler.
Referred to [1] for this fix.

Fixes: 7e2c3e17fe2c ("eal/arm64: add 128-bit atomic compare exchange")
Cc: stable@dpdk.org

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e0d5896bd356cd577f9710a02d7a474cdf58426b

Signed-off-by: Ruifeng Wang <a548d51fbc42485a8ba807711a537e88c2b59dd2@arm.com>
Reviewed-by: Jerin Jacob <352c4d4f9291b869992ddb67daa45ddc149fed30@marvell.com>
Reviewed-by: Honnappa Nagarahalli <01ccf438b971cc1d8919c8a7f18443cae9429d8b@arm.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk