Added CMYK support for ICC profiles.

Added CMYK support for ICC profiles.

Changed ICC parsing/SkGammas/SkColorLookUpTable to handle non-3-channel
inputs. Parsed CMYK A2B ICC profiles. Integrated this with SkJpegCodec
(the only file that supports CMYK) and SkColorSpaceXform_A2B to allow
parsing and color xforming of ICC CMYK images.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=5197
CQ_INCLUDE_TRYBOTS=skia.primary:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD

Change-Id: Id6619f63f04071f79cd2d84321857dfa269ad3aa
Reviewed-on: https://skia-review.googlesource.com/5197
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Matt Sarett <msarett@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Leon Scroggins <scroggo@google.com>