i2c: omap: simplify errata check

omap_i2c_dev is allocated with kzalloc(),
so we need not initialize b_hw to zero.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>