ArmPlatformPkg: reorganize PL011 code

The PL011 code in ArmPlatformPkg is organized in a weird way: there is
a single PL011Uart.h header file under Include/Drivers containing both
register definitions and function entry points. The PL011Uart library
itself is in Drivers/ but it is actually a library.

So let's clean this up: add a new PL011UartLib library class and associated
header file containing only the library prototypes, and move the library
itself under Library/ using a new GUID, with the register definitions moved
into a local header file.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.inf

@@ -0,0 +1,43 @@
+#/** @file
+#
+#  Component description file for PL011Uart module
+#
+#  Copyright (c) 2011-2016, ARM Ltd. All rights reserved.<BR>
+#
+#  This program and the accompanying materials
+#  are licensed and made available under the terms and conditions of the BSD License
+#  which accompanies this distribution.  The full text of the license may be found at
+#  http://opensource.org/licenses/bsd-license.php
+#
+#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#**/
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = PL011UartLib
+  FILE_GUID                      = 6a2c5714-8910-44f0-861f-804abc18ce39
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = PL011UartLib
+
+[Sources.common]
+  PL011Uart.h
+  PL011UartLib.c
+
+[LibraryClasses]
+  DebugLib
+  IoLib
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+
+[FixedPcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdSerialBaudRate
+
+  gArmPlatformTokenSpaceGuid.PL011UartInteger
+  gArmPlatformTokenSpaceGuid.PL011UartFractional
+  gArmPlatformTokenSpaceGuid.PL011UartRegOffsetVariant