sh: clkfwk: fix up compiler warnings.

  CC      drivers/sh/clk/core.o
drivers/sh/clk/core.c: In function 'clk_round_parent':
drivers/sh/clk/core.c:574: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'unsigned int'
drivers/sh/clk/core.c:594: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'unsigned int'

Signed-off-by: Paul Mundt <lethal@linux-sh.org>