ARC: Remove unneeded Kconfig entry NO_DMA

Architectures only need a Kconfig entry for NO_DMA if it is possible
that its value will be 'y'. For arc its value will always be 'n', making
it pointless. Remove it.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>