i2c-omap: fix build for !CONFIG_SUSPEND

fix the build break when !CONFIG_SUSPEND

drivers/i2c/busses/i2c-omap.c:1173: error: lvalue required as unary '&' operand
make[3]: *** [drivers/i2c/busses/i2c-omap.o] Error 1
make[2]: *** [drivers/i2c/busses] Error 2
make[1]: *** [drivers/i2c] Error 2
make: *** [drivers] Error 2

Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>