ARM: dts: imx28-tx28: remove undocumented aliases

ARM: dts: imx28-tx28: remove undocumented aliases

Remove undocumented aliases, which is not used in kernel to fix
CHECK_DTBS warnings.
  arch/arm/boot/dts/nxp/mxs/imx28-tx28.dtb: aliases: 'lcdif_23bit_pins', 'lcdif_24bit_pins', 'reg_can_xcvr', 'spi_gpio', 'spi_mxs' do not match any of the regexes: '^[a-z][a-z0-9\\-]*$', '^pinctrl-[0-9]+$'
        from schema $id: http://devicetree.org/schemas/aliases.yaml

Signed-off-by: Frank Li <Frank.Li@nxp.com>