arm64: dts: qcom: qcs8550: introduce qcs8550 dtsi

arm64: dts: qcom: qcs8550: introduce qcs8550 dtsi

QCS8550 is derived from SM8550. The difference between SM8550 and
QCS8550 is QCS8550 doesn't have modem RF system. QCS8550 is mainly used
in IoT products.
QCS8550 firmware has different memory map compared to SM8550.
The memory map will be runtime added through bootloader.
There are 3 types of reserved memory regions here:
1. Firmware related regions which aren't shared with kernel.
    The device tree source in kernel doesn't need to have node to indicate
the firmware related reserved information. Bootloader converys the
information by updating devicetree at runtime.
    This will be described as: UEFI saves the physical address of the
UEFI System Table to dts file's chosen node. Kernel read this table and
add reserved memory regions to efi config table. Current reserved memory
region may have reserved region which was not yet used, release note of
the firmware have such kind of information.
2. Firmware related memory regions which are shared with Kernel
    The device tree source in the kernel needs to include nodes that
indicate fimware-related shared information. A label name is suggested
because this type of shared information needs to be referenced by
specific drivers for handling purposes.
    Unlike previous platforms, QCS8550 boots using EFI and describes
most reserved regions in the ESRT memory map. As a result, reserved
memory regions which aren't relevant to the kernel(like the hypervisor
region) don't need to be described in DT.
3. Remoteproc regions.
    Remoteproc regions will be reserved and then assigned to subsystem
firmware later.
Here is a reserved memory map for this platform:
 0x80000000 +-------------------+
            |                   |
            | Firmware Related  |
            |                   |
 0x8a800000 +-------------------+
            |                   |
            | Remoteproc Region |
            |                   |
 0xa7000000 +-------------------+
            |                   |
            | Kernel Available  |
            |                   |
 0xd4d00000 +-------------------+
            |                   |
            | Firmware Related  |
            |                   |
0x100000000 +-------------------+

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Tengfei Fan <quic_tengfan@quicinc.com>
Link: https://lore.kernel.org/r/20240618072202.2516025-3-quic_tengfan@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>