arm64: dts: freescale: imx93-phyboard-segin: Fix SD-card pinctrl

arm64: dts: freescale: imx93-phyboard-segin: Fix SD-card pinctrl

Until now, all usdhc2 (SD-card) pinctrl labels pointed to one pinctrl
group "usdhc2grp" which was overwritten twice by the 100 and 200 MHz
modes. Fix this by using unique pinctrl names.

Additionally, adjust MX93_PAD_SD2_CLK__USDHC2_CLK pad drive-strength
according to values obtained by measurements from the PHYTEC hardware
department to improve signal integrity.

Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>