staging: rts5208: Eliminate the use of Camel Case in file sd.h

Cleans up checks of "Avoid CamelCase" in file sd.h
Even though the constant "DCM_LOW_FREQUENCY_MODE_SET" is defined and never used,
it's useful to keep it because it documents the device.

Signed-off-by: Gabriela Bittencourt <gabrielabittencourt00@gmail.com>

Link: https://lore.kernel.org/r/20191031230243.3462-4-gabrielabittencourt00@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>