Revert "Revert "hikey: Switch second ARCH variant from deprecated armv7-a-neon to armv8-a""

This reverts commit d985b20ab1a6f52a1576b8e12589a6907e832955.

Bug: 64900226
Test: Manual
Change-Id: I348e2df8988e191403b84fe0559e3102122ed61a
diff --git a/BoardConfigCommon.mk b/BoardConfigCommon.mk
index ed87ef8..20a39d8 100644
--- a/BoardConfigCommon.mk
+++ b/BoardConfigCommon.mk
@@ -5,7 +5,7 @@
 
 # Secondary Arch
 TARGET_2ND_ARCH := arm
-TARGET_2ND_ARCH_VARIANT := armv7-a-neon
+TARGET_2ND_ARCH_VARIANT := armv8-a
 TARGET_2ND_CPU_ABI := armeabi-v7a
 TARGET_2ND_CPU_ABI2 := armeabi