dt-bindings: i2c: i2c-emev2: Rename bindings documentation file

Rename the bindings documentation file for Renesas EMEV2 IIC controller
from i2c-emev2.txt to renesas,iic-emev2.txt.

This is part of an ongoing effort to name bindings documentation files for
Renesas IP blocks consistently, in line with the compat strings they
document.

Signed-off-by: Simon Horman <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

MAINTAINERS

···
 RENESAS EMEV2 I2C DRIVER
 M:	Wolfram Sang <[e-mail]>
 S:	Supported
-F:	Documentation/devicetree/bindings/i2c/i2c-emev2.txt
+F:	Documentation/devicetree/bindings/i2c/renesas,iic-emev2.txt
 F:	drivers/i2c/busses/i2c-emev2.c
 
 RENESAS ETHERNET DRIVERS