Remove fpga RAM

This removes the ram from inside the FPGA. All RAM is now located in the
external SDRAM instead.

The ROM is still in the FPGA to allow easier programming.

hw/fpga/super6502.qsf

@@ -356,7 +356,6 @@ set_global_assignment -name SYSTEMVERILOG_FILE uart.sv
 set_global_assignment -name SYSTEMVERILOG_FILE addr_decode.sv
 set_global_assignment -name SYSTEMVERILOG_FILE bb_spi_controller.sv
 set_global_assignment -name SYSTEMVERILOG_FILE super6502.sv
-set_global_assignment -name QIP_FILE ram.qip
 set_global_assignment -name SDC_FILE super6502.sdc
 set_global_assignment -name QIP_FILE rom.qip
 set_global_assignment -name SYSTEMVERILOG_FILE HexDriver.sv