Set TARGET_2ND_ARCH_VARIANT to armv8-a

Bullhead is armv8 device. Setting TARGET_2ND_ARCH_VARIANT to armv8-a,
instead of armv7-a-neon, can silence the related warning during build.

Bug: 68012286
Test: lunch aosp_bullhead; make -j
Change-Id: I0989c3d4185334dbfe0a3d79d3595d8dff8abd2b
1 file changed