Add overclocking option -oc to workaround a NVIDIA driver bug (forcefully set to p2 state when using cuda)

include/capture/nvfbc.h

@@ -12,7 +12,8 @@ typedef struct {
     int fps;
     vec2i pos;
     vec2i size;
-    bool direct_capture; /* temporary disabled */
+    bool direct_capture;
+    bool overclock;
 } gsr_capture_nvfbc_params;
 
 gsr_capture* gsr_capture_nvfbc_create(const gsr_capture_nvfbc_params *params);

include/capture/xcomposite_cuda.h

@@ -11,6 +11,7 @@ typedef struct {
     Window window;
     bool follow_focused; /* If this is set then |window| is ignored */
     vec2i region_size; /* This is currently only used with |follow_focused| */
+    bool overclock;
 } gsr_capture_xcomposite_cuda_params;
 
 gsr_capture* gsr_capture_xcomposite_cuda_create(const gsr_capture_xcomposite_cuda_params *params);