revert(zynqmp): remove EM SMC handler

EM support was out of SMC SIP range that's why has been moved to SIP
range 0x3000 by commit acbae3998bd8 ("fix(zynqmp): move EM SMC range
to SIP range").
But after another investigation was found that this interface has no
user in any our SW and likely never adopted by anybody else. That's
why simply remove it. If there is any user it can be added back but
as TF-A size is challenging removing unused code is very welcome.
Origin code was added by commit 504925f99da0 ("xilinx: zynqmp: Add
support for Error Management").

Change-Id: I2d9222d7dde507400893e06f7f12e1713ce6bc9a
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/plat/xilinx/zynqmp/pm_service/pm_svc_main.h b/plat/xilinx/zynqmp/pm_service/pm_svc_main.h
index c1781f3..3c3082f 100644
--- a/plat/xilinx/zynqmp/pm_service/pm_svc_main.h
+++ b/plat/xilinx/zynqmp/pm_service/pm_svc_main.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2023, Advanced Micro Devices Inc. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -13,8 +14,4 @@
 uint64_t pm_smc_handler(uint32_t smc_fid, uint64_t x1, uint64_t x2, uint64_t x3,
 			uint64_t x4, const void *cookie, void *handle,
 			uint64_t flags);
-
-uint64_t em_smc_handler(uint32_t smc_fid, uint64_t x1, uint64_t x2, uint64_t x3,
-			uint64_t x4, const void *cookie, void *handle,
-			uint64_t flags);
 #endif /* PM_SVC_MAIN_H */