icecc-create-env: Use program interpreter for deps

ldd cannot always be used to determine a program's dependencies
correctly, particularly when the program specifies an alternate program
interpreter (dynamic loader). This commonly happens when using a
uninative tarball. Instead, determine the program's requested
interpreter, and ask it to list the dependencies.

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>