The only way to do this is self join or use code from a front end tool.
select comb, cnta, cntb, cntc
from ( select comb, count(*) 'cnta'
from quickvote a
where locaiton = 'z'
) a
inner join ( select comb, count(*) 'cnta'
from quickvote a
where locaiton = 'y'
) b
on a.comb = b.comb
...