u-boot-qoriq: add quote mark to avoid build error when multiple u-boot configs are built
The the following build error:
./poky/p4080ds/tmp/work/p4080ds-poky-linux/u-boot-qoriq/2015.01+fslgit-r0/temp/run.do_deploy.16948: line 172: P4080DS_config: command not found
UBOOT_MACHINES= P4080DS_config P4080DS_SECURE_BOOT_config P4080DS_SDCARD_config P4080DS_SPIFLASH_config
Signed-off-by: Zhenhua Luo <zhenhua.luo@freescale.com> Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
