Implement GPU syncpoints (#980)

* Implement GPU syncpoints

This adds support for GPU syncpoints on the GPU backend & nvservices.

Everything that was implemented here is based on my researches,
hardware testing of the GM20B and reversing of nvservices (8.1.0).

Thanks to @fincs for the informations about some behaviours of the pusher
and for the initial informations about syncpoints.

* syncpoint: address gdkchan's comments

* Add some missing logic to handle SubmitGpfifo correctly

* Handle the NV event API correctly

* evnt => hostEvent

* Finish addressing gdkchan's comments

* nvservices: write the output buffer even when an error is returned

* dma pusher: Implemnet prefetch barrier

lso fix when the commands should be prefetch.

* Partially fix prefetch barrier

* Add a missing syncpoint check in QueryEvent of NvHostSyncPt

* Address Ac_K's comments and fix GetSyncpoint for ChannelResourcePolicy == Channel

* fix SyncptWait & SyncptWaitEx cmds logic

* Address ripinperi's comments

* Address gdkchan's comments

* Move user event management to the control channel

* Fix mm implementation, nvdec works again

* Address ripinperi's comments

* Address gdkchan's comments

* Implement nvhost-ctrl close accurately + make nvservices dispose channels when stopping the emulator

* Fix typo in MultiMediaOperationType

Ryujinx.Graphics.Gpu/State/MethodOffset.cs

@@ -8,6 +8,15 @@ namespace Ryujinx.Graphics.Gpu.State
     /// </remarks>
     enum MethodOffset
     {
+        BindChannel                     = 0x00,
+        FenceValue                      = 0x1c,
+        FenceAction                     = 0x1d,
+        WaitForIdle                     = 0x44,
+        MacroUploadAddress              = 0x45,
+        SendMacroCodeData               = 0x46,
+        MacroBindingIndex               = 0x47,
+        BindMacro                       = 0x48,
+        SetMmeShadowRamControl          = 0x49,
         I2mParams                       = 0x60,
         LaunchDma                       = 0x6c,
         LoadInlineData                  = 0x6d,
@@ -15,6 +24,7 @@ namespace Ryujinx.Graphics.Gpu.State
         CopySrcTexture                  = 0x8c,
         DispatchParamsAddress           = 0xad,
         Dispatch                        = 0xaf,
+        SyncpointAction                 = 0xb2,
         CopyBuffer                      = 0xc0,
         RasterizeEnable                 = 0xdf,
         CopyBufferParams                = 0x100,