That simply doesn't matter, GDDR5 is GPU RAM/Video memory which is faster than DDR4 ram.
The only thing that matters with GPU and Motherboard is PCIE 3.0,2.0,2.x,,1.0 is it x16,x8,x4.
That most matters.
The GPU has it's own memory controller, so ram type on the card doesn't matter. For years boards ran DDR2, while GPUs ran DDR3. Or boards ran DDR3 while GPUs ran (g)DDR5. Because the GPU has it's own memory controller it simply doesn't matter. As Robert said, make sure the slot type matches/is compatible.
I know they don't teach logic in schools anymore, but did you really think they'd sell out of all the DDR5 GPUs they can make, if nobody can use them because there are no DDR5 motherboards yet?
I have the first DDR5 graphics card, which came out 10 years ago back in 2008. Back then, everybody used DDR2 motherboards and I assure you that nobody would've bought such GPUs if they had to wait 11 years until 2019 to plug them into DDR5 motherboards.