gpu-compute: Add missing override in render driver
gpu-compute: Add missing override in render driver

This fixes the build error in the clang-11 compiler check for GCN3_X86.

Change-Id: I2245589182b80811b8bc07409196adca98899213
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47479
Reviewed-by: Matt Sinclair <d2406197fb1bedd1e23c70c50c510ff0e9ab0f5b@gmail.com>
Maintainer: Matt Sinclair <d2406197fb1bedd1e23c70c50c510ff0e9ab0f5b@gmail.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5