mfd: da9063: Convert headers to SPDX

Covnert the headers of the source and include files to SPDX.
And fix some typos in the descriptions ("interrupt" instead of "I2C").

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Steve Twiss <stwiss.opensource@diasemi.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Lee Jones <lee.jones@linaro.org>