Slave SDI is not supported

[M0stafaRady]

The controller supports SPI and SQI. However there is another mode supported by the slave memory 23LC1024 called SDI (Serial Dual Interface). The RTL have 3 modes and of them is dual but it's not behaving like the slave is expected a dual mode would behave.
The RTL dual mode starts by sending the command using only SIO0:

EF_PSRAM_CTRL_V2/hdl/rtl/EF_PSRAM_CTRL_V2.v

Line 186 in afc59c6

assign douten_qspi = (counter < 8) ? 4'b0001 :

However the slave expected the command to be sent over SIO0 and SIO1:

EF_PSRAM_CTRL_V2/verify/utb/23LC1024.v

Lines 232 to 234 in afc59c6

	`SDIMODE: begin
	if (ClockCounter == 3) InstRegister <= {DataShifterI[05:00],SO_SIO1,SI_SIO0};
	end