ARM: dts: imx6ull: Use the correct name for ESAI_TX0

ARM: dts: imx6ull: Use the correct name for ESAI_TX0

According to the i.MX6ULL Reference Manual, pad CSI_DATA07 may
have the ESAI_TX0 functionality, not ESAI_T0.

Also, NXP's i.MX Config Tools 10.0 generates dtsi with the
MX6ULL_PAD_CSI_DATA07__ESAI_TX0 naming, so fix it accordingly.

There are no devicetree users in mainline that use the old name,
so just remove the old entry.

Fixes: f8ca22b8de32 ("arm: dts: imx6ull: add pinctrl defines")
Reported-by: George Makarov <georgemakarov1@gmail.com>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Peng Fan <peng.fan@nxp.com>