dt-bindings: mmc: drop unneeded quotes

Cleanup by removing unneeded quotes from refs and redundant blank lines.
No functional impact except adjusting to preferred coding style.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> # for Renesas controllers
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230120085722.171965-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

dt-binding: mmc: Add mmc yaml file for Sunplus SP7021

Add MMC YAML file for Sunplus SP7021.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
Link: https://lore.kernel.org/r/8c8fbc29524819d8ab45a4fe75311b3b7b567650.1669023361.git.tonyhuang.sunplus@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>