clk: Unexport __clk_of_table

This symbol doesn't need to be exported to clk providers anymore.
Originally, it was hidden inside clk.c, but then OMAP needed to get
access to it in commit 819b4861 ("CLK: ti: add init support for
clock IP blocks"), but eventually that code also changed in commit
c08ee14c

 ("clk: ti: change clock init to use generic of_clk_init")
and we were left with this exported. Move this back into clk.c so that
it isn't exposed anymore.

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