Any motherboard can be the foundation of a 'gaming' computer simply by playing a game on it.
The term is generally used if the computer had a discrete video card, instead of only having the CPU's integrated graphics. For example, the Dell XPS usually comes with a Nvidia GTX 745 video card. However, that video card is very slow. Although you could play games on the computer (on low settings), it is technically a 'gaming' computer.
'Gaming' and 'multimedia' are marketing terms. Nothing more, nothing less.
The motherboard you listed has a PCI-E 3.0 x16 slot that will work fine with any PCI-E video card (including a 980ti). You only have to ensure the power supply you select can provide enough power for the video card you select. The gaming performance will only be limited by the graphic card you select.
A i5-6500 will handle any 'multimedia' task or game you throw at it. It is a very fast and effecient processor.