With this, I was able to successfully compile a defconfig kernel for the
sheevaplug, though I didn't actually try to run it (not having a
sheevaplug myself).
For native compiles, the most significant difference is that the
platform's kernel target is built directly rather than hoping the
default make target will pull it in.
Also some stylistic improvements along the way.
Signed-off-by: Shea Levy <shea@shealevy.com>