powerpc/b4860: Updated default hwconfig to enable only cpc2

CPC1 is not being enabled by default as powerpc is supposed to
use only CPC2. Though by editing hwconfig en_cpc option,
CPC1 can also be enabled.

Signed-off-by: Shaveta Leekha <shaveta@freescale.com>
Signed-off-by: Sandeep Singh <Sandeep@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>