powerpc/corenet_ds: move SATA config to board configuration

powerpc/corenet_ds: move SATA config to board configuration

board configuration file is included before asm/config_mpc85xx.h.
however, CONFIG_FSL_SATA_V2 is defined in asm/config_mpc85xx.h.
it will never take effective in the board configuration file for
this kind of code :

 #ifdef CONFIG_FSL_SATA_V2
 ...
 #endif

To solve this problem, move CONFIG_FSL_SATA_V2 to board
configuration header file.

This patch reverts Timur's
commit:3e0529f742e893653848494ffb9f7cd0d91304bf

Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>