Makefiles: add separate static recipe and allow for cross-compiles
mkbootimg: fix padding calculation for 2ndstage loader

Change-Id: I8db844cbc52896e51886b725fb86fd1b0fa57899
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
mkbootimg: turn on -Werror

- Deal with signedness issues

Change-Id: I61211165eb4ce0fa9a2edeebb3f97fb0ffc62d34
mkbootimg: also deal with signedness on dt_size
unpackbootimg: turn on -Werror
libmincrypt: suppress warning messages

- deal with implict declaration issue

Change-Id: I253f1412a696c4811ade70a931fb1c01b31c62a5
Remove declaration of unused static variable

The declaration is useless and triggers a warning with clang 3.5 (in
code that's built with -Werror)

Change-Id: I8fc42178df264509dcce6e1f1ba318bf849307e3
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>