dt-bindings: update sifive clint compatible string

Add the "canaan,k210-clint" compatible string to the Sifive clint
bindings to indicate the use of the "sifive,clint0" IP block in the
Canaan Kendryte K210 SoC. The description of the compatible string
property is also updated to reflect this addition.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Documentation/devicetree/bindings/timer/sifive,clint.yaml

@@ -23,15 +23,19 @@ description:
 properties:
   compatible:
     items:
-      - const: sifive,fu540-c000-clint
+      - enum:
+          - sifive,fu540-c000-clint
+          - canaan,k210-clint
       - const: sifive,clint0
 
     description:
-      Should be "sifive,<chip>-clint" and "sifive,clint<version>".
+      Should be "<vendor>,<chip>-clint" and "sifive,clint<version>".
       Supported compatible strings are -
       "sifive,fu540-c000-clint" for the SiFive CLINT v0 as integrated
-      onto the SiFive FU540 chip, and "sifive,clint0" for the SiFive
-      CLINT v0 IP block with no chip integration tweaks.
+      onto the SiFive FU540 chip, "canaan,k210-clint" for the SiFive
+      CLINT v0 as integrated onto the Canaan Kendryte K210 chip, and
+      "sifive,clint0" for the SiFive CLINT v0 IP block with no chip
+      integration tweaks.
       Please refer to sifive-blocks-ip-versioning.txt for details
 
   reg: