ssl_rsa.c now basically deals with private-key functions, so rename to
reflect that.
Change-Id: Ia87ed4c0f9b34af134844e2eeb270fc45ff3f23f
Reviewed-on: https://boringssl-review.googlesource.com/13583
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>