grub: fixup grub SRC_URI to use split-horizon
grub: fixup grub SRC_URI to use split-horizon

Signed-off-by: Alex Stewart <04cdb2793e4fb0120cc30d1c823099f3862701f4@ni.com>
Acked-by: Ken Sharp <e6c8ad8f54d15df4645e8aaf3f7a209bc3688570@ni.com>
(cherry picked from commit 6eac4c3e4d63369b62e72d5351e243a93cf2c965)

ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt,ni/meta-nilrt