NEON implementation for Adler32

The checksum is calculated in the uncompressed PNG data and can be made
much faster by using SIMD.

Tests in ARMv8 yielded an improvement of about 3x (e.g. walltime
was 350ms x 125ms for a 4096x4096 bytes executed 30 times).

This alone yields a performance boost for PNG decoding ranging
from 5% to 18% depending on a few factors (SoC, battery status, etc).
adler32 use NEON instruction

10% benefit for PNG decoding

CRs-Fixed: 2420347

Change-Id: I51d4a257b8a51b6839c0fd7fede8c0fa5fb21cce