powerpc/configs: Drop no longer needed CONFIG_SCSI

Since commit 67f6d665 ("powerpc: convert amigaone_defconfig to use
libata PATA drivers") we no longer need to set CONFIG_SCSI in our
defconfigs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/configs/amigaone_defconfig

@@ -45,7 +45,6 @@ CONFIG_PARPORT_PC_FIFO=y
 CONFIG_BLK_DEV_FD=y
 CONFIG_BLK_DEV_LOOP=y
 CONFIG_BLK_DEV_RAM=y
-CONFIG_SCSI=y
 CONFIG_BLK_DEV_SD=y
 CONFIG_CHR_DEV_ST=y
 CONFIG_BLK_DEV_SR=y