Update opentitan-peripheral robot to match the spi_device implementation

Renode code base enabled spi_device at
https://github.com/renode/renode/commit/44fa51ea4f2ecd5c6a5e71124eebc35a5727f085

Update our robot script to match the change

Change-Id: I4f76fafb796bce9ee36b9b326d6afd5b4667d850
diff --git a/opentitan_peripherals_test.robot b/opentitan_peripherals_test.robot
index e77362e..4781e4e 100644
--- a/opentitan_peripherals_test.robot
+++ b/opentitan_peripherals_test.robot
@@ -84,7 +84,6 @@
     Execute Command             include @sim/config/shodan_infrastructure/AddressRangeStub.cs
     Execute Command             machine LoadPlatformDescription @sim/config/platforms/opentitan-earlgrey-cw310.repl
     Execute Command             showAnalyzer ${UART}
-    Execute Command             sysbus SilenceRange <0x40050000 0x2000>
     Execute Command             machine LoadPlatformDescriptionFromString ${LEDS}
     Execute Command             machine LoadPlatformDescriptionFromString ${SPI_FLASH}
     Execute Command             sysbus.otp_ctrl LoadVmem @${OTP_VMEM}
@@ -370,4 +369,3 @@
     Wide Register Should Be Equal   29  0x4f0d4b819f24f0c164341d3c26628bdb5763bcdf63388709e0654fefeb0953c2
     Wide Register Should Be Equal   30  0x2167f87de9ee7ac7ffa3d88bab123192aee492924efa2ec9b55098e068ba2fa1
     Wide Register Should Be Equal   31  0x37adadaef9dbff5e738800755466a52c67a8c2216978ad1b257694340f09b7c8
-