ARM: shmobile: Use r8a7740 suffix for i2c, mmcif, fsi2 compat strings

Add "renesas,*-r8a7740" to the compatible strings for consistency with other
devices.

Signed-off-by: Ulrich Hecht <ulrich.hecht@gmail.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>