drm/amdgpu: fix 32-bit build warning

Casting a pointer to a 64-bit type causes a warning on 32-bit targets:

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c:473:24: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
          lower_32_bits((uint64_t)wptr));
                        ^
drivers/gpu/drm/amd/amdgpu/amdgpu.h:1701:53: note: in definition of macro 'WREG32'
 #define WREG32(reg, v) amdgpu_mm_wreg(adev, (reg), (v), 0)
                                                     ^
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c:473:10: note: in expansion of macro 'lower_32_bits'
          lower_32_bits((uint64_t)wptr));
          ^~~~~~~~~~~~~

The correct method is to cast to 'uintptr_t'.

Fixes: d5a114a6c5f7 ("drm/amdgpu: Add GFXv9 kfd2kgd interface functions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c

@@ -470,9 +470,9 @@ static int kgd_hqd_load(struct kgd_dev *kgd, void *mqd, uint32_t pipe_id,
 		WREG32(SOC15_REG_OFFSET(GC, 0, mmCP_HQD_PQ_WPTR_HI),
 		       upper_32_bits(guessed_wptr));
 		WREG32(SOC15_REG_OFFSET(GC, 0, mmCP_HQD_PQ_WPTR_POLL_ADDR),
-		       lower_32_bits((uint64_t)wptr));
+		       lower_32_bits((uintptr_t)wptr));
 		WREG32(SOC15_REG_OFFSET(GC, 0, mmCP_HQD_PQ_WPTR_POLL_ADDR_HI),
-		       upper_32_bits((uint64_t)wptr));
+		       upper_32_bits((uintptr_t)wptr));
 		WREG32(SOC15_REG_OFFSET(GC, 0, mmCP_PQ_WPTR_POLL_CNTL1),
 		       get_queue_mask(adev, pipe_id, queue_id));
 	}