Input: sx8654 - convert #defined flags to BIT(x)

Some of the #defined register values are one-bit flags. Convert them to
use the BIT(x) macro instead of 1 byte hexadecimal values. This improves
readability and clarifies the intent.

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>