llama: add default load-mode auto, which avoids mmap on iGPUs (llama/26081)

* llama: add new default load-mode auto which picks mmap unless a non-Metal iGPU is used

* Update ggml/src/ggml-hexagon/ggml-hexagon.cpp

Co-authored-by: Max Krasnyansky <maxk@qti.qualcomm.com>

* set mmap_support to false on OpenCL backend

* fix order of load modes

* use -1 for auto

* resolve load mode auto earlier to correctly pick gpu host or cpu memory

* add load mode auto to llama-bench

* bump virtgpu api version, regenerate docs

---------

Co-authored-by: Piotr Wilkin (ilintar) <piotr.wilkin@syndatis.com>
Co-authored-by: Max Krasnyansky <maxk@qti.qualcomm.com>
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

ggml/src/ggml-virtgpu/backend/backend-dispatched-device.cpp

@@ -111,6 +111,7 @@ uint32_t backend_device_get_props(apir_encoder * enc, apir_decoder * dec, virgl_
     apir_encode_bool_t(enc, &props.caps.host_buffer);
     apir_encode_bool_t(enc, &props.caps.buffer_from_host_ptr);
     apir_encode_bool_t(enc, &props.caps.events);
+    apir_encode_bool_t(enc, &props.caps.mmap_support);
 
     return 0;
 }

ggml/src/ggml-virtgpu/backend/shared/api_remoting.h

@@ -7,7 +7,7 @@
 #include <cstdint>
 
 #define APIR_PROTOCOL_MAJOR 0
-#define APIR_PROTOCOL_MINOR 1
+#define APIR_PROTOCOL_MINOR 2
 
 #define APIR_HANDSHAKE_MAGIC 0xab1e