freedreno: Fix GCC build error.

../src/freedreno/vulkan/tu_device.c:900:4: error: initializer element is not constant
    .minImageTransferGranularity = (VkExtent3D) { 1, 1, 1 },
    ^

Suggested-by: Kristian Høgsberg <krh@bitplanet.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110698


Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
(cherry picked from commit d4e70be7)