dt-bindings: remoteproc: stm32_rproc: update syscon descriptions

Align other syscon descriptions with st,syscfg-m4-state and
st,syscfg-rsc-tbl descriptions by suppressing the cells
description.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NArnaud Pouliquen <arnaud.pouliquen@st.com>
Link: https://lore.kernel.org/r/20201014125441.2457-4-arnaud.pouliquen@st.comSigned-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml

@@ -38,9 +38,6 @@ properties:
   st,syscfg-tz:
     description:
       Reference to the system configuration which holds the RCC trust zone mode
-      - Phandle of syscon block.
-      - The offset of the RCC trust zone mode register.
-      - The field mask of the RCC trust zone mode.
     $ref: "/schemas/types.yaml#/definitions/phandle-array"
     maxItems: 1
 
@@ -91,9 +88,6 @@ properties:
     $ref: "/schemas/types.yaml#/definitions/phandle-array"
     description: |
       Reference to the system configuration which holds the remote
-        1st cell: phandle to syscon block
-        2nd cell: register offset containing the deep sleep setting
-        3rd cell: register bitmask for the deep sleep bit
     maxItems: 1
 
   st,syscfg-m4-state: