nv30, nv40: move last files to nvfx/ and rm -rf nv30 nv40

This is the last nvfx unification patch.

nv[34]0_fragtex.c are moved to the common directory
nv[34]0_shader.h are renamed to nv[34]0_vertprog.h and moved to
the common directory

The separate nv30 and nv40 directories are removed from the build
system
diff --git a/configure.ac b/configure.ac
index eb271e9..0f51097 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1360,7 +1360,7 @@
     [enable_gallium_nouveau=no])
 if test "x$enable_gallium_nouveau" = xyes; then
     GALLIUM_WINSYS_DRM_DIRS="$GALLIUM_WINSYS_DRM_DIRS nouveau"
-    GALLIUM_DRIVERS_DIRS="$GALLIUM_DRIVERS_DIRS nouveau nvfx nv30 nv40 nv50"
+    GALLIUM_DRIVERS_DIRS="$GALLIUM_DRIVERS_DIRS nouveau nvfx nv50"
 fi
 
 dnl