When chaging the cpu and memory frequency we need to disable the
external memory interface (EMI) for a small time. This can
underflow the dma and cause some breakage. Hopefully the SSP
controller handles this gracefully by stopping the clock and the
I2C probably handles this naturally because the clock can be
streched anyway. However the LCDIF has a special setting for this
which needs to be enable, otherwise it will send garbage to the
LCD. No other block is known to suffer from this currently but
this issue might have more unexpected consequences.
Change-Id: Ide154cad87929f2bf6cc419ac1d2ff33e30eec66
