omap4430-panda: Prefer u-boot-git and remove extra custom x-load
omap4430-panda: Prefer u-boot-git and remove extra custom x-load

* Switch to using u-boot-git (instead of u-boot-sakoman)
   * Remove reference to custom x-load
   * Remove extra image depends (which will come from common include)

Signed-off-by: Roger Monk <d23a2d7364ff5b9274b46f5bc00c2488a2111ac3@ti.com>
Signed-off-by: Koen Kooi <aeb23945acf582c79fe8e7da695ed6eac02acbbd@ti.com>

rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal,rascalmicro/openembedded-rascal