arm: omap: i2c: fix compile warning

Fix the following compile warning:
arch/arm/plat-omap/i2c.c:120:13: warning:
'omap_pm_set_max_mpu_wakeup_lat_compat' defined but not used
arch/arm/plat-omap/i2c.c:125:38: warning: 'omap_i2c_latency'
defined but not used

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>