ARM: shmobile: r8a7779: Remove unused r8a7779_init_delay()

Remove the now unused r8a7779_init_delay() function.

Based on work for the r8a7740 SoC by Magnus Damm.

Cc: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>