dt-bindings: pinctrl: drive-strength doesn't default to 2 if unspecified

If the drive-strength isn't specified in the device tree then it
doesn't actually default to 2. Instead, it defaults to whatever the
heck the BIOS left it at. If the BIOS doesn't touch it then that means
it's whatever the heck the initial state of the pin was when the SoC
booted.
Reported-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20220111140519.1.Ie2662d6289af1e9758b14b37149703c846d5f509@changeidSigned-off-by: NLinus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/qcom,tlmm-common.yaml

@@ -73,7 +73,6 @@ $defs:
     properties:
       drive-strength:
         enum: [2, 4, 6, 8, 10, 12, 14, 16]
-        default: 2
         description:
           Selects the drive strength for the specified pins, in mA.