u-boot, u-boot-fw-utils-cross, u-boot-mkimage: Upgrade to 2013.07

u-boot, u-boot-fw-utils-cross, u-boot-mkimage: Upgrade to 2013.07

This upgrades the U-Boot based recipes for 2013.07 release.

This removes the 2011.03, 2011.06 and 2013.01.01 versions so we keep a
single one in core. The following recipes has been upgraded:

 - u-boot (remove old versions)
 - u-boot-mkimage (remove old versions)
 - u-boot-fw-utils -> u-boot-fw-utils-cross (renamed and reworked)

The u-boot-fw-utils-cross recipe has been reworked as it uses the
UBOOT_MACHINE to find default environment for use so it is indeed a
cross binary and not a native one.

(From OE-Core rev: c5fff5748e0aaf7e135fdd464c2104b1d3cbfd5a)

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>