socfpga: Move board/socfpga_cyclone5 to board/socfpga

socfpga: Move board/socfpga_cyclone5 to board/socfpga

Because the SOCFPGA platform will include support for Cyclone V and
Arria V FPGA parts, renaming socfpga_cyclone5 folder to socfpga to
be more generic.

Signed-off-by: Dinh Nguyen <[email protected]>
Reviewed-by: Pavel Machek <[email protected]>
Cc: Chin Liang See <[email protected]>
Cc: Wolfgang Denk <[email protected]>
CC: Pavel Machek <[email protected]>
Cc: Tom Rini <[email protected]>
v2:
- Add Reviewed-by: Pavel Machek
- Cc: Tom Rini