The Raspberry Pi platform with Secure Boot enabled currently fails to build with error: Module type [DXE_RUNTIME_DRIVER] is not supported by library instance [/home/appveyor/projects/rpi4/edk2/MdePkg/Library/DxeRngLib/DxeRngLib.inf] Add the missing class to fix this issue. Signed-off-by: Pete Batard <pete@akeo.ie> Reviewed-by: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com> Reviewed-by: Andrei Warkentin <awarkentin@vmware.com> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>