smbios: fix matching issues for table types

commit 738b3466 ("smbios: Fallback to the default DT if sysinfo nodes are missing")
allowed the code to fallback and fill in SMBIOS tables with properties
from the compatible and product nodes of the DT, in case the
'smbios,sysinfo' node is missing.
That works fine for Type1/2 tables, but for other types we need to
match the smbios,sysinfo subnode name as well. So add it to the
smbios_ctx and check it during the sysinfo <-> DT mathcing

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>