parisc: drivers.c: Fix section mismatches

Fix two section mismatches in drivers.c:
1) Section mismatch in reference from the function alloc_tree_node() to
   the function .init.text:create_tree_node().
2) Section mismatch in reference from the function walk_native_bus() to
   the function .init.text:alloc_pa_dev().

Signed-off-by: Helge Deller <deller@gmx.de>