add DPM scheduler with EDM formulation (#7120)

* add DPM scheduler with EDM formulation

* set sigmas in init

* add _compute_sigmas

* Apply suggestions from code review

Co-authored-by: Pedro Cuenca <[email protected]>

* address some review comments

* up,

* add tests

---------

Co-authored-by: Pedro Cuenca <[email protected]>

Author: patil-suraj

src/diffusers/__init__.py

@@ -144,6 +144,7 @@
             "DPMSolverMultistepInverseScheduler",
             "DPMSolverMultistepScheduler",
             "DPMSolverSinglestepScheduler",
+            "EDMDPMSolverMultistepScheduler",
             "EDMEulerScheduler",
             "EulerAncestralDiscreteScheduler",
             "EulerDiscreteScheduler",
@@ -527,6 +528,7 @@
             DPMSolverMultistepInverseScheduler,
             DPMSolverMultistepScheduler,
             DPMSolverSinglestepScheduler,
+            EDMDPMSolverMultistepScheduler,
             EDMEulerScheduler,
             EulerAncestralDiscreteScheduler,
             EulerDiscreteScheduler,

src/diffusers/schedulers/__init__.py

@@ -52,6 +52,7 @@
     _import_structure["scheduling_dpmsolver_multistep"] = ["DPMSolverMultistepScheduler"]
     _import_structure["scheduling_dpmsolver_multistep_inverse"] = ["DPMSolverMultistepInverseScheduler"]
     _import_structure["scheduling_dpmsolver_singlestep"] = ["DPMSolverSinglestepScheduler"]
+    _import_structure["scheduling_edm_dpmsolver_multistep"] = ["EDMDPMSolverMultistepScheduler"]
     _import_structure["scheduling_edm_euler"] = ["EDMEulerScheduler"]
     _import_structure["scheduling_euler_ancestral_discrete"] = ["EulerAncestralDiscreteScheduler"]
     _import_structure["scheduling_euler_discrete"] = ["EulerDiscreteScheduler"]
@@ -145,6 +146,7 @@
         from .scheduling_dpmsolver_multistep import DPMSolverMultistepScheduler
         from .scheduling_dpmsolver_multistep_inverse import DPMSolverMultistepInverseScheduler
         from .scheduling_dpmsolver_singlestep import DPMSolverSinglestepScheduler
+        from .scheduling_edm_dpmsolver_multistep import EDMDPMSolverMultistepScheduler
         from .scheduling_edm_euler import EDMEulerScheduler
         from .scheduling_euler_ancestral_discrete import EulerAncestralDiscreteScheduler
         from .scheduling_euler_discrete import EulerDiscreteScheduler