internal/egl: move app/internal/egl

We're about to move package app/headless to gpu/headless, and it needs
the egl package.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/headless/headless_egl.go

@@ -5,7 +5,7 @@
 package headless
 
 import (
-	"gioui.org/app/internal/egl"
+	"gioui.org/internal/egl"
 )
 
 func newGLContext() (context, error) {

app/internal/window/egl_android.go

@@ -10,7 +10,7 @@ import "C"
 import (
 	"unsafe"
 
-	"gioui.org/app/internal/egl"
+	"gioui.org/internal/egl"
 )
 
 type context struct {

app/internal/window/egl_wayland.go

@@ -8,7 +8,7 @@ import (
 	"errors"
 	"unsafe"
 
-	"gioui.org/app/internal/egl"
+	"gioui.org/internal/egl"
 )
 
 /*

app/internal/window/egl_windows.go

@@ -3,7 +3,7 @@
 package window
 
 import (
-	"gioui.org/app/internal/egl"
+	"gioui.org/internal/egl"
 )
 
 type glContext struct {

app/internal/window/egl_x11.go

@@ -7,7 +7,7 @@ package window
 import (
 	"unsafe"
 
-	"gioui.org/app/internal/egl"
+	"gioui.org/internal/egl"
 )
 
 type x11Context struct {