relocate_sdk.py: skip debug files from relocation

relocate_sdk.py: skip debug files from relocation

Debug files only have debug symbols hence don't need
to be relocated. Relocation script throws errors when
run on the debug files. This change skips these files
that have zero size.

(From OE-Core rev: 132e8bfd499c713eb63075fd6380317b60f0bd27)

(From OE-Core rev: 93b73b2495f9cb18741837c5437de629adfd3780)

Signed-off-by: Nikunj Kela <nkela@cisco.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>