i2c: tegra: add PROTOCOL_MANGLING as supported functionality.

The Tegra i2c driver supports the I2C_M_IGNORE_NAK and hence
returning I2C_FUNC_PROTOCOL_MANGLING as supported functionality.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>