image_types_tegra.bbclass: fix uboot suffix, alignment
image_types_tegra.bbclass: fix uboot suffix, alignment

- remove use of UBOOT_SUFFIX variable, which is only
  available in the u-boot recipe

- add IMAGE_ROOTFS_ALIGNMENT setting

Signed-off-by: Matt Madison <1fa2ef4755a9226cb9a0a4840bd89b158ac71391@madison.systems>

madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra,madisongh/meta-tegra,jackmitch/meta-tegra,jackmitch/meta-tegra,jackmitch/meta-tegra