clk: mvebu: ap806: be more explicit on what SaR is

"SaR" means Sample at Reset. DIP switches can be changed on the board,
their states at reset time is available through a register read.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lkml.kernel.org/r/20190805100310.29048-6-miquel.raynal@bootlin.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>