ARM: shmobile: r8a7778: Remove wrapper r8a7778_init_delay()

r8a7778_init_delay() just calls shmobile_init_delay(), hence replace
calls to it by direct calls to shmobile_init_delay().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>