ppc: Move clock fields to arch_global_data

Move vco_out, cpm_clk, scc_clk, brg_clk into arch_global_data and tidy
up. Leave pci_clk on its own since this should really depend only on
CONFIG_PCI and not any particular chip type.

Signed-off-by: Simon Glass <sjg@chromium.org>
4 files changed