update neon config in libjpeg turbo

libjpeg.gyp

Index: libjpeg.gyp
diff --git a/libjpeg.gyp b/libjpeg.gyp
index 491ede8efb00324613b620861e70f23bfe5f36a8..6156d79f06813d46e59999082e451b354ce9bd98 100644
--- a/libjpeg.gyp
+++ b/libjpeg.gyp
@@ -155,11 +155,11 @@
           ],
         }],
         # The ARM SIMD implementation can be used for devices that support
-        # the NEON instruction set. This is done dynamically by probing CPU
-        # features at runtime, so always compile it for ARMv7-A devices.
+        # the NEON instruction set. This can safely be done dynamically by
+        # probing CPU features at runtime, if you wish.
         [ 'target_arch=="arm"', {
           'conditions': [
-            [ 'armv7 == 1 or arm_neon == 1', {
+            [ 'arm_version >= 7 and (arm_neon == 1 or arm_neon_optional == 1)', {
               'sources': [
                 'simd/jsimd_arm.c',
                 'simd/jsimd_arm_neon.S',