ARM: pipelined NEON implementation of bilinear scaled 'src_8888_0565'

ARM: pipelined NEON implementation of bilinear scaled 'src_8888_0565'

Benchmark on ARM Cortex-A8 r1p3 @600MHz, 32-bit LPDDR @166MHz:
 Microbenchmark (scaling 2000x2000 image with scale factor close to 1x):
  before: op=1, src=20028888, dst=10020565, speed=33.59 MPix/s
  after:  op=1, src=20028888, dst=10020565, speed=46.25 MPix/s

Benchmark on ARM Cortex-A8 r2p2 @1GHz, 32-bit LPDDR @200MHz:
 Microbenchmark (scaling 2000x2000 image with scale factor close to 1x):
  before: op=1, src=20028888, dst=10020565, speed=63.86 MPix/s
  after:  op=1, src=20028888, dst=10020565, speed=84.22 MPix/s