dt-bindings: mmc: dwcmshc-sdhci: Fix resets array validation

The binding defines tuple-style reset-names items for some
compatibles, which implicitly enforces a fixed array length
via JSON Schema.

Defining global maxItems for resets and reset-names causes these
constraints to be intersected via allOf, resulting in an effective
minItems equal to the global maxItems. This leads to dtbs_check
failures reporting reset arrays as too short, even when the DTS
provides the correct number of entries.

Fixes: 30009a21f257 ("dt-bindings: mmc: sdhci-of-dwcmshc: Add Eswin EIC7700")
Co-developed-by: Pritesh Patel <pritesh.patel@einfochips.com>
Signed-off-by: Pritesh Patel <pritesh.patel@einfochips.com>
Signed-off-by: Huan He <hehuan1@eswincomputing.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>