arm64: dts: rockchip: correct vqmmc voltage for rk3399 platforms

The vcc_sd or vcc_sdio used for IO voltage for sdmmc and sdio
interface on rk3399 platform have a limitation that it can't be
larger than 3.0v, otherwise it has a potential risk for the chip.
Correct all of them.

Fixes: 171582e0 ("arm64: dts: rockchip: add support for firefly-rk3399 board")
Fixes: 2c66fc34 ("arm64: dts: rockchip: add RK3399-Q7 (Puma) SoM")
Fixes: 8164a84c

 ("arm64: dts: rockchip: Add support for rk3399 sapphire SOM")
Cc: stable@vger.kernel.org
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Klaus Goger <klaus.goger@theobroma-systems.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>