arch/powerpc: Fix mapping of Freescale SerDes protocols

arch/powerpc: Fix mapping of Freescale SerDes protocols

The number of supported serdes protocols on Freescale SoCs
has increased over time. Until now, an u64 variable have been
initialized on boot with the configured protocols. However,
since this number has increased (enum srds_prtcl has more
than 64 values), 64 bits are no longer sufficient to hold track
of all the configured protocols.
This patch replaces the u64 map values with static arrays.
To keep track of the number of serdes protocols, the
SERDES_PRCTL_COUNT vale has been added at the end of
enum srds_prtcl. This value must always be the last one.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>