ARM: shmobile: Get rid of redundant EMEV2 mach callbacks

Update the EMEV2 specific SoC callbacks to get rid
of the calls to of_clk_init() and of_platform_populate().
Those calls are by default executed by the functions in
the shared ARM code in case the SoC specific mach
callbacks are NULL.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>