platform: goldfish: pipe: Remove license boilerplate

The boilerplate license is not necessary when the SPDX line is
present.

Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

platform: goldfish: pipe: Separate the host interface to a separate header

These are several enums that must kept in sync with the host side.
This change explicitly separates them into a dedicated header file.

Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>