accel/ivpu: Fix warning due to undefined CONFIG_PROC_FS

Change #if to #ifdef CONFIG_PROC_FS to fix warning reported by test robot:
drivers/accel/ivpu/ivpu_drv.c:458:5: warning: "CONFIG_PROC_FS" is not defined, evaluates to 0 [-Wundef]

Fixes: 63cc028484ab ("accel/ivpu: Add fdinfo support for memory statistics")
Reviewed-by: Maciej Falkowski <[e-mail]>
Reviewed-by: [e-mail]
Signed-off-by: Karol Wachowski <[e-mail]>
Link: https://patch.msgid.link/[e-mail]

drivers/accel/ivpu/ivpu_drv.c

···
 static const struct file_operations ivpu_fops = {
 	.owner		= THIS_MODULE,
 	DRM_ACCEL_FOPS,
-#if CONFIG_PROC_FS
+#ifdef CONFIG_PROC_FS
 	.show_fdinfo = drm_show_fdinfo,
 #endif
 };
···
 	.ioctls = ivpu_drm_ioctls,
 	.num_ioctls = ARRAY_SIZE(ivpu_drm_ioctls),
 	.fops = &ivpu_fops,
-#if CONFIG_PROC_FS
+#ifdef CONFIG_PROC_FS
 	.show_fdinfo = drm_show_memory_stats,
 #endif