Rename GrTexture/Proxy/Priv mip map members/functions

Change-Id: Ib55cab0ef76ced165d1936e7d084edc7fa579c55
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/304737
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
47 files changed