ARM: shmobile: Use shmobile_init_late() on r8a7740

Hook up ->init_late for r8a7740 to initialize Suspend-to-RAM
and CPUIdle in case of C-code less board support for r8a7740.

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>