Remove fIsMipMapped from GrSurfaceDesc

Part 3 of 3 for relanding of https://skia-review.googlesource.com/c/skia/+/42083

Bug: skia:
Change-Id: I98c5406015213df5d11a0101df8722da6845157e
Reviewed-on: https://skia-review.googlesource.com/44464
Reviewed-by: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
11 files changed