egl: const _eglDriver

Converted using `s/_EGLDriver/const _EGLDriver/g` and dropped a couple
of irrelevant changes in comments, in the `_EGL_DRIVER_TYPECAST()` macro
and the typedef itself.

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6129>
diff --git a/src/egl/main/eglsurface.c b/src/egl/main/eglsurface.c
index 2024271..f70cbef 100644
--- a/src/egl/main/eglsurface.c
+++ b/src/egl/main/eglsurface.c
@@ -429,7 +429,7 @@
 
 
 EGLBoolean
-_eglQuerySurface(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surface,
+_eglQuerySurface(const _EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surface,
                  EGLint attribute, EGLint *value)
 {
    switch (attribute) {
@@ -593,7 +593,7 @@
  * Default fallback routine - drivers might override this.
  */
 EGLBoolean
-_eglSurfaceAttrib(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surface,
+_eglSurfaceAttrib(const _EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surface,
                   EGLint attribute, EGLint value)
 {
    EGLint confval;
@@ -718,7 +718,7 @@
 
 
 EGLBoolean
-_eglBindTexImage(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surface,
+_eglBindTexImage(const _EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surface,
                  EGLint buffer)
 {
    EGLint texture_type = EGL_PBUFFER_BIT;
@@ -748,7 +748,7 @@
 }
 
 EGLBoolean
-_eglReleaseTexImage(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surf,
+_eglReleaseTexImage(const _EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surf,
                     EGLint buffer)
 {
    /* Just do basic error checking and return success/fail.
@@ -785,7 +785,7 @@
 
 
 EGLBoolean
-_eglSwapInterval(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surf,
+_eglSwapInterval(const _EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *surf,
                  EGLint interval)
 {
    return EGL_TRUE;