clk: bcm: clk-iproc-pll: Demote kernel-doc abuse

Fixes the following W=1 kernel build warning(s):

drivers/clk/bcm/clk-iproc-pll.c:712: warning: Function parameter or member 'pll' not described in 'iproc_pll_sw_cfg'

Cc: Michael Turquette <[e-mail]>
Cc: Stephen Boyd <[e-mail]>
Cc: Ray Jui <[e-mail]>
Cc: Scott Branden <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/bcm/clk-iproc-pll.c

···
 	.set_rate = iproc_clk_set_rate,
 };
 
-/**
+/*
  * Some PLLs require the PLL SW override bit to be set before changes can be
  * applied to the PLL
  */