Fix typos in arch_list and do variant validation

Test: m nothing
Change-Id: Icfbc9f886a1e16abe02bf6c61671b8187a699942
diff --git a/android/arch_list.go b/android/arch_list.go
index d68a0d1..79ad4af 100644
--- a/android/arch_list.go
+++ b/android/arch_list.go
@@ -22,38 +22,12 @@
 		"armv7-a-neon",
 		"armv8-a",
 		"armv8-2a",
-		"cortex-a7",
-		"cortex-a8",
-		"cortex-a9",
-		"cortex-a15",
-		"cortex-a53",
-		"cortex-a53-a57",
-		"cortex-a55",
-		"cortex-a72",
-		"cortex-a73",
-		"cortex-a75",
-		"cortex-a76",
-		"krait",
-		"kryo",
-		"kryo385",
-		"exynos-m1",
-		"exynos-m2",
 	},
 	Arm64: {
-		"armv8_a",
-		"armv8_a_branchprot",
-		"armv8_2a",
+		"armv8-a",
+		"armv8-a-branchprot",
+		"armv8-2a",
 		"armv8-2a-dotprod",
-		"cortex-a53",
-		"cortex-a55",
-		"cortex-a72",
-		"cortex-a73",
-		"cortex-a75",
-		"cortex-a76",
-		"kryo",
-		"kryo385",
-		"exynos-m1",
-		"exynos-m2",
 	},
 	X86: {
 		"amberlake",
@@ -87,6 +61,41 @@
 	},
 }
 
+var cpuVariants = map[ArchType][]string{
+	Arm: {
+		"cortex-a7",
+		"cortex-a8",
+		"cortex-a9",
+		"cortex-a15",
+		"cortex-a53",
+		"cortex-a53.a57",
+		"cortex-a55",
+		"cortex-a72",
+		"cortex-a73",
+		"cortex-a75",
+		"cortex-a76",
+		"krait",
+		"kryo",
+		"kryo385",
+		"exynos-m1",
+		"exynos-m2",
+	},
+	Arm64: {
+		"cortex-a53",
+		"cortex-a55",
+		"cortex-a72",
+		"cortex-a73",
+		"cortex-a75",
+		"cortex-a76",
+		"kryo",
+		"kryo385",
+		"exynos-m1",
+		"exynos-m2",
+	},
+	X86:    {},
+	X86_64: {},
+}
+
 var archFeatures = map[ArchType][]string{
 	Arm: {
 		"neon",