aspeed: Rename u-boot recipes

Append an -aspeed suffix to Aspeed u-boot and u-boot-fw-utils
recipes to match convention of other upstream BSP layers like
meta-fsl-arm.

Tested: Built palmetto/spoon images and booted in QEMU
Change-Id: I88ce2062876674ea9c104a97cc0bf2c83f2b1fcd
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
5 files changed