MdeModulePkg/Bus/Spi/SpiBus: Adding SpiBus Drivers

Added SpiBus DXE and SMM drivers. This code translates SPI requests from
the application layer into SPI Bus transactions on the SPI host
controller. The code is responsible for checking if the transaction is
valid, then setting up the SPI clock and chip select properly before
passing the bus transaction to the host controller.

Platform Initialization Spec 1.7 volume 5 section 18.1.6

Bugzilla #4753

Cc: Abner Chang <abner.chang@amd.com>
Cc: Abdul Lateef Attar <AbdulLateef.Attar@amd.com>
Signed-off-by: Brit Chesley <brit.chesley@amd.com>
Reviewed-by: Abner Chang <abner.chang@amd.com>

MdeModulePkg/Bus/Spi/SpiBus/SpiBus.uni

@@ -0,0 +1,10 @@
+// /** @file
+//
+// Copyright (C) 2024 Advanced Micro Devices, Inc. All rights reserved.<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+#string STR_PROPERTIES_MODULE_NAME
+#language en-US   "SPI Bus driver"