dt-bindings: pinctrl: toshiba,visconti: Fix number of items in groups

commit 316e361b5d upstream.

The "groups" property can hold multiple entries (e.g.
toshiba/tmpv7708-rm-mbrc.dts file), so allow that by dropping incorrect
type (pinmux-node.yaml schema already defines that as string-array) and
adding constraints for items.  This fixes dtbs_check warnings like:

  toshiba/tmpv7708-rm-mbrc.dtb: pinctrl@24190000 (toshiba,tmpv7708-pinctrl):
    pwm-pins:groups: ['pwm0_gpio16_grp', 'pwm1_gpio17_grp', 'pwm2_gpio18_grp', 'pwm3_gpio19_grp'] is too long

Fixes: 1825c1fe00 ("pinctrl: Add DT bindings for Toshiba Visconti TMPV7700 SoC")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/pinctrl/toshiba,visconti-pinctrl.yaml

@@ -50,7 +50,7 @@ patternProperties:
       groups:
         description:
           Name of the pin group to use for the functions.
-        $ref: /schemas/types.yaml#/definitions/string
+        items:
           enum: [i2c0_grp, i2c1_grp, i2c2_grp, i2c3_grp, i2c4_grp,
                  i2c5_grp, i2c6_grp, i2c7_grp, i2c8_grp,
                  spi0_grp, spi0_cs0_grp, spi0_cs1_grp, spi0_cs2_grp,
@@ -62,6 +62,8 @@ patternProperties:
                  pwm2_gpio10_grp, pwm2_gpio14_grp, pwm2_gpio18_grp,
                  pwm3_gpio7_grp, pwm3_gpio11_grp, pwm3_gpio15_grp,
                  pwm3_gpio19_grp, pcmif_out_grp, pcmif_in_grp]
+        minItems: 1
+        maxItems: 8
 
       drive-strength:
         enum: [2, 4, 6, 8, 16, 24, 32]