Add Kconfig toggles for a few more extended options that are useful for reducing size and improving performance of EROFS images. Descriptions of the config options were taken from the erofs-utils manpage. Signed-off-by: Jan Čermák <sairon@sairon.cz> [Arnout: fix Config.in help text and indentation] Signed-off-by: Arnout Vandecappelle <arnout@mind.be>