Fix a number of typos, including:

     * "compatble" -> "compatible"
     * "eanbeld" -> "enabled"
     * "envrionment" -> "environment"
     * "FTD" -> "FDT" (for "flattened device tree")
     * "ommitted" -> "omitted"
     * "overriden" -> "overridden"
     * "partiton" -> "partition"
     * "propogate" -> "propagate"
     * "resourse" -> "resource"
     * "rest in piece" -> "rest in peace"
     * "suport" -> "support"
     * "varible" -> "variable"

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>