Use magma::page_size()/magma::page_shift()

These provide a posix-compatible way to resolve these values that
enables linux build targets.

Test: $ tiles_ctl add
      fuchsia-pkg://fuchsia.com/spinning_square_view#meta/spinning_square_view.cmx
Change-Id: I9a4b60996bfd887e0d77d8007ded2be22a1305b8
1 file changed