ni-systemimage: add missing RDEPENDS
ni-systemimage: add missing RDEPENDS

The nisystemimage script depends on the find utility from findutils and
the functions.common source file from ni-utils.

Add RDEPENDS on those utils.

Signed-off-by: Alex Stewart <04cdb2793e4fb0120cc30d1c823099f3862701f4@ni.com>

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