u-boot: Upgrade CV u-boot to 2018.05
u-boot: Upgrade CV u-boot to 2018.05

This update resolves the build issue for Yocto 2.6 (Thud),
as it uses the version of U-Boot which has a build conflict
of libfdt-devel resolved.

Signed-off-by: Andrey Zhizhikin <288e5ce7581ec10ade4dc09f0fe51e9e90e0bd6f@gmail.com>

dwesterg/meta-altera,kraj/meta-altera,kraj/meta-altera,kraj/meta-altera,dwesterg/meta-altera