A hacky way to do that is to use yum list or yum check-update to see what packages would have updated then use yum update with a partial package name and wildcard to just do some of them by wildcarding against the first letter(s) of the names, for example:
odds are there will be a mixture of packages starting with particular letters so just look at the list
and do just a few depending on how many start with a particular letter (suppose 'a' 'b' and 'c' give you
about 20 matching packages):
later do some more and so on until done.
This isn't perfect, sometimes just a small number of package wildcards will pull in a lot more due to dependencies. So
you need to look at the number of packages that set of wildcards would pull in (yum update will show you and then wait at the "Y/n" prompt),
if it's more than you want exclude some more for example dropping the 'c' matches from the above to cut back: