nexys_base: use 50MHz sys_clk (to run DDR3 @ 200Mhz for now) and minicon sdram controller
nexys_base: use 50MHz sys_clk (to run DDR3 @ 200Mhz for now) and minicon sdram controller

cr1901/HDMI2USB-litex-firmware,mithro/HDMI2USB-litex-firmware,cr1901/HDMI2USB-litex-firmware,mithro/HDMI2USB-litex-firmware,cr1901/HDMI2USB-litex-firmware,cr1901/HDMI2USB-litex-firmware,mithro/HDMI2USB-litex-firmware,mithro/HDMI2USB-litex-firmware