Workaround a GCC warning to unbreak ARM build.

Reported by:	ian
Add gpio and clock bits for A10/A20's EMAC ethernet controller driver, such as:
- EMAC gpio configuration
- EMAC clock activation

Approved by:	stas (mentor)
Add Static Random Access Memory controller driver for A10/A20.
A10/A20's SRAM is used by devices, such as CPU, EMAC,
for extra fast memory or as cache.

Approved by:	stas (mentor)
Add EMAC 10/100 Ethernet controller driver for A10/A20.
It is available mostly in A10 devices like Hackberry, Marsboard,
Mele A1000, A2000, A100 HTPC, cubieboard1 and A20 device
like cubieboard2.
TX performance can be improved using both channels 0 and 1.
RX performance is poor and needs improvement with the assistance of
external DMA controller in case there is bulk TCP receiver.

Reviewed by:	yongari@
Approved by:	stas (mentor)
Add EMAC and SRAM controller entries to FDT.
Add EMAC device to kernel config files and
enable EMAC, SRAM drivers for build.

Approved by:	stas (mentor)
Use the standard __used macro instead of a bare __attribute__.

Submitted by:	bde
Add a missing semicolong, noticed by the gnu dt compiler.