mpc83xx: Remove cache config from MPC8360ERDK.h

The MPC8360ERDK board support patch is added before
the commit 2c5b48fc
so, miss clean up it.

The patch clean up the miss cache config.

Signed-off-by: Dave Liu <daveliu@freescale.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>