fix VkImportMemoryResourceInfoMESA definition
Without this, the struct is ignored by the encoder and the decoder.
Caught by modified vkcube that imports a minigbm bo. I did not bother updating virglrenderer and Mesa yet as the test also requires mesa/mesa!10437 (merged) and virglrenderer!517 (merged). With the two MRs and this fix applied, I can
- allocate a minigbm bo with linear tiling
- import the bo as VkDeviceMemory
- render to the bo using Vulkan
- map the bo for reading (which triggers a transfer from the host storage to the guest storage of the bo)
- verify a cube is rendered
/cc @zzyiwei