drivers/crypto/fsl: enable raw data instead of von Neumann data

The sampling of the oscillator can be done in multiple modes for
generating the entropy value. By default, this is set to von
Neumann. This patch changes the sampling to raw data, since it
has been discovered that the generated entropy has a better
'quality'.

Signed-off-by: Alex Porosanu <alexandru.porosanu@freescale.com>
Acked-by: Ruchika <Gupta&lt;ruchika.gupta@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>