amd/amdkfd: drop unused KFD_IOCTL_SVM_FLAG_UNCACHED flag

Was leftover from GC 9.4.3 bring up and is currently
unused.  Drop it for now.

Cc: Philip.Yang@amd.com
Cc: rajneesh.bhardwaj@amd.com
Cc: Felix.Kuehling@amd.com
Reviewed-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_svm.c

@@ -1154,7 +1154,7 @@ svm_range_get_pte_flags(struct kfd_node *node,
 	uint64_t pte_flags;
 	bool snoop = (domain != SVM_RANGE_VRAM_DOMAIN);
 	bool coherent = flags & KFD_IOCTL_SVM_FLAG_COHERENT;
-	bool uncached = flags & KFD_IOCTL_SVM_FLAG_UNCACHED;
+	bool uncached = false; /*flags & KFD_IOCTL_SVM_FLAG_UNCACHED;*/
 	unsigned int mtype_local;
 
 	if (domain == SVM_RANGE_VRAM_DOMAIN)

include/uapi/linux/kfd_ioctl.h

@@ -623,8 +623,6 @@ enum kfd_mmio_remap {
 #define KFD_IOCTL_SVM_FLAG_GPU_READ_MOSTLY     0x00000020
 /* Keep GPU memory mapping always valid as if XNACK is disable */
 #define KFD_IOCTL_SVM_FLAG_GPU_ALWAYS_MAPPED   0x00000040
-/* Uncached access to memory */
-#define KFD_IOCTL_SVM_FLAG_UNCACHED 0x00000080
 
 /**
  * kfd_ioctl_svm_op - SVM ioctl operations