Revert "Implement d117_predictor using Neon"

Revert "Implement d117_predictor using Neon"

This reverts commit 360e9069b6cc1dd3a004728b876fb923413f4b11.

This causes ASan errors:
[ RUN      ] VP9/TestVectorTest.MD5Match/1
=================================================================
==837858==ERROR: AddressSanitizer: stack-buffer-overflow on address
0xffff82ecad40 at pc 0x000000c494d4 bp 0xffffe1695800 sp 0xffffe16957f8
READ of size 16 at 0xffff82ecad40 thread T0
    #0 0xc494d0 in vpx_d117_predictor_32x32_neon (test_libvpx+0xc494d0)
    #1 0x1040b34 in vp9_predict_intra_block (test_libvpx+0x1040b34)
    #2 0xf8feec in decode_block (test_libvpx+0xf8feec)
    #3 0xf8f588 in decode_partition (test_libvpx+0xf8f588)
    #4 0xf7be5c in vp9_decode_frame (test_libvpx+0xf7be5c)
    ...
Address 0xffff82ecad40 is located in stack of thread T0 at offset 64 in
frame
    #0 0x103fd3c in vp9_predict_intra_block (test_libvpx+0x103fd3c)

  This frame has 2 object(s):
    [32, 64) 'left_col.i' <== Memory access at offset 64 overflows this
                              variable
    [96, 176) 'above_data.i'

Change-Id: I058213364617dfe1036126c33a3307f8288d9ae0