clk: versal: Mark versal_clock_setup() as static

clk: versal: Mark versal_clock_setup() as static

Fix the following sparse and compile time warning
triggered with W=1:

drivers/clk/clk_versal.c:605:5:
warning: no previous prototype for 'versal_clock_setup'
[-Wmissing-prototypes]
605 | int versal_clock_setup(void)

Signed-off-by: Venkatesh Yadav Abbarapu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michal Simek <[email protected]>