docs: Add inital PowerVR driver documentation

Signed-off-by: Karmjit Mahil <Karmjit.Mahil@imgtec.com>
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/8048
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23992>

docs/drivers/powervr.rst

@@ -0,0 +1,46 @@
+PowerVR
+=======
+
+PowerVR is a Vulkan driver for Imagination Technologies PowerVR GPUs, starting
+with those based on the Rogue architecture.
+
+The driver is **not yet fully conformant** so it requires exporting
+``PVR_I_WANT_A_BROKEN_VULKAN_DRIVER=1`` to the environment before running any
+Vulkan content.
+
+The following hardware is currently in active development:
+
+========= =========== ============== ======= ==========
+Product   Series      B.V.N.C        Vulkan  Conformant
+========= =========== ============== ======= ==========
+GX6250    Series 6XT  4.40.2.51      1.0     No
+AXE-1-16M A-Series    33.15.11.3     1.0     No
+BXS-4-64  B-Series    36.53.104.796  1.0     No
+========= =========== ============== ======= ==========
+
+In some cases, a product name is shared across multiple BVNCs so to check for
+support make sure the BVNC matches the one listed. As the feature set and
+hardware issues can vary between BVNCs, additional driver changes might be
+necessary even for devices sharing the same product name.
+
+Hardware documentation can be found at: https://docs.imgtec.com/
+
+Note: GPUs prior to Series6 do not have the hardware capabilities required to
+support Vulkan and therefore cannot be supported by this driver.
+
+Chat
+----
+
+PowerVR developers and users hang out on IRC at ``#powervr`` on OFTC. Note
+that registering and authenticating with ``NickServ`` is required to prevent
+spam. `Join the chat. <https://webchat.oftc.net/?channels=powervr>`_
+
+Hardware glossary
+-----------------
+
+.. glossary:: :sorted:
+
+   BVNC
+      Set of four numbers used to uniquely identify each GPU (Series6 onwards).
+      This is used to determine the GPU feature set, along with any known
+      hardware issues.

docs/index.rst

@@ -89,6 +89,7 @@ Linux, FreeBSD, and other operating systems.
    drivers/lima
    drivers/llvmpipe
    drivers/panfrost
+   drivers/powervr
    drivers/radv
    drivers/svga3d
    drivers/v3d