clk: Allow force setting clock defaults before relocation

Since 291da96b ("clk: Allow clock defaults to be set during re-reloc
state for SPL only") it has been impossible to set clock defaults before
relocation. This is annoying on boards without SPL, since there is no way
to set clock defaults before U-Boot proper. In particular, the aisram rate
must be changed before relocation on the K210, since U-Boot will hang if we
try and change the rate while we are using aisram.

To get around this, extend the stage parameter to allow force setting
defaults, even if they would be otherwise postponed for later. A device
tree property was decided against because of the concerns in the original
commit thread about the overhead of repeatedly parsing the device tree.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>