feat(msm8916): initial platform port

Introduce the bare mimimum base of the msm8916 BL31 port. This is
pretty much just a standard platform "skeleton" with CPU/memory
initialization and an UART driver. This allows booting into
e.g. U-Boot with working UART output.

Note that the plat/qti/msm8916 port is completely separate and does not
make use of anything in plat/qti/common at the moment. The main reason
for that is that plat/qti/common is heavily focused around having a
binary "qtiseclib" component, while the MSM8916 port is fully
open-source (and therefore somewhat limited to publicly documented
functionality).

In the future it might be possible to re-use some of the open-source
parts in plat/qti/common (e.g. spmi_arb.c or pm_ps_hold.c) but it's
not strictly required for the basic functionality supported so far.

Change-Id: I7b4375df0f947b3bd1e55b0b52b21edb6e6d175b
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
diff --git a/plat/qti/msm8916/msm8916_topology.c b/plat/qti/msm8916/msm8916_topology.c
new file mode 100644
index 0000000..4d0ed8f
--- /dev/null
+++ b/plat/qti/msm8916/msm8916_topology.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <plat/common/platform.h>
+
+#include <platform_def.h>
+
+static const unsigned char plat_power_domain_tree_desc[PLAT_MAX_PWR_LVL + 1] = {
+	PLATFORM_SYSTEM_COUNT,
+	PLATFORM_CLUSTER_COUNT,
+	PLATFORM_MAX_CPUS_PER_CLUSTER,
+};
+
+int plat_core_pos_by_mpidr(u_register_t mpidr)
+{
+	unsigned int core = MPIDR_AFFLVL0_VAL(mpidr);
+
+	if (MPIDR_AFFLVL3_VAL(mpidr) > 0 ||
+	    MPIDR_AFFLVL2_VAL(mpidr) > 0 ||
+	    MPIDR_AFFLVL1_VAL(mpidr) > 0 ||
+	    core >= PLATFORM_MAX_CPUS_PER_CLUSTER) {
+		return -1;
+	}
+
+	return core;
+}
+
+const unsigned char *plat_get_power_domain_tree_desc(void)
+{
+	return plat_power_domain_tree_desc;
+}