OvmfPkg/AcpiPlatformDxe: consolidate #includes and [LibraryClasses]

OvmfPkg/AcpiPlatformDxe: consolidate #includes and [LibraryClasses]

- #include only such public headers in "AcpiPlatform.h" that are required
  by the function declarations and type definitions introduced in
  "AcpiPlatform.h". Don't use "AcpiPlatform.h" as a convenience #include
  file.

- In every file, list every necessary public #include individually, with
  an example identifier that's actually consumed.

- Remove unnecessary lib classes, add unlisted lib classes.

- Remove unnecessary #include directives, add unlisted #include
  directives.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2122
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20210526201446.12554-11-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>