ASoC: cros_ec_codec: fix uninitialized memory read

ASoC: cros_ec_codec: fix uninitialized memory read

gcc points out a memory area that is copied to a device
but not initialized:

sound/soc/codecs/cros_ec_codec.c: In function 'i2s_rx_event':
arch/x86/include/asm/string_32.h:83:20: error: '*((void *)&p+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   83 |   *((int *)to + 1) = *((int *)from + 1);

Initialize all the unused fields to zero.

Fixes: 727f1c71c780 ("ASoC: cros_ec_codec: refactor I2S RX")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20201203225458.1477830-1-arnd@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>