yes, drawing skills are a plus - they really help with conceptualising your ideas. in first year i was an art major, graphics minor - and did studies in painting/drawing and life drawing - it really helped. Now i've switched to a Graphic design major. usually a viscomm course will cover fundamentals in drawing in the first year, so don't worry too much.
i didn't have to present my portfolio, as i had done HSC art. (here the prereq is either hsc visual arts OR portfolio & interview, both if quotas on student numbers need to be applied.)
a lot of the main design is carried out on computer but all the concept sketches must be mapped out and done by hand. you include these in your process diaries, which are always assessed. having said that, you don't need to be excellent at drawing (that comes with practice) but if you can show your creativity/good conceptual thinking, and if you have good colour and spatial sense, well that is more important in graphic design.
Drawing is only really important if you want to become an illustrator.