Here is the last Windows 7 AMD Driver for your APU Processor: https://www.amd.com/en/support/apu/amd-series-processors/amd-a6-series-apu-for-desktops/a6-5400k-rad...
But if you have a supported GPU card like any RX series GPU cards you can't use both drivers since the Integrated Graphics would be incompatible with your supported AMD GPU card.
If the latest Windows 7 driver "Release Notes" shows your GPU card as being compatible then you can use the same driver for both GPUs, Intergrated and Discrete.
Otherwise you will need to disable your Integrated Graphics and just use your GPU card or vice versa.