media: rockchip: rkisp1: add support for v12 isp variants

The rkisp1 evolved over soc generations and the rk3326/px30 introduced
the so called v12 - probably meaning v1.2.

Add the new register definitions.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Reviewed-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/driver-api/media/drivers/rkisp1.rst

@@ -0,0 +1,43 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+The Rockchip Image Signal Processor Driver (rkisp1)
+===================================================
+
+Versions and their differences
+------------------------------
+
+The rkisp1 block underwent some changes between SoC implementations.
+The vendor designates them as:
+
+- V10: used at least in rk3288 and rk3399
+- V11: declared in the original vendor code, but not used
+- V12: used at least in rk3326 and px30
+- V13: used at least in rk1808
+- V20: used in rk3568 and beyond
+
+Right now the kernel supports rkisp1 implementations based
+on V10 and V12 variants. V11 does not seem to be actually used
+and V13 will need some more additions but isn't researched yet,
+especially as it seems to be limited to the rk1808 which hasn't
+reached much market spread.
+
+V20 on the other hand will probably be used in future SoCs and
+has seen really big changes in the vendor kernel, so will need
+quite a bit of research.
+
+Changes from V10 to V12
+-----------------------
+
+- V12 supports a new CSI-host implementation but can still
+  also use the same implementation from V10
+- The module for lens shading correction got changed
+  from 12bit to 13bit width
+- The AWB and AEC modules got replaced to support finer
+  grained data collection
+
+Changes from V12 to V13
+-----------------------
+
+The list for V13 is incomplete and needs further investigation.
+
+- V13 does not support the old CSI-host implementation anymore