Provide the CLK framework callbacks related to get/set clock duty cycle if
the related SCMI clock supports OEM extended configurations.
CC: Michael Turquette <mturquette@xxxxxxxxxxxx>
CC: Stephen Boyd <sboyd@xxxxxxxxxx>
CC: linux-clk@xxxxxxxxxxxxxxx
Signed-off-by: Cristian Marussi <cristian.marussi@xxxxxxx>