The specifications table 28, page 30 in the AD9545 rev C data sheet states clearly the high level of SPI pins CSB, SCLK, SDO and SDIO depend on VDDIOA. The VDDIOA supply may be 1.8V, 2.5V or 3.3V. So if you need the AD9545 SPI to function with 3.3V logic, you need to use VDDIOA=3.3V.
Please note that the Mx pins and RESETB pin depend of VDDIOA or VDDIOB voltages. So if you use VDDIOA=3.3V to solve your SPI compatibility issues, make sure you know about the voltage levels of these pins, specially if you use them as inputs. The evaluation board has VDDIOA and VDDIOB connected together at 1.8V, but you can use then at different voltages.
I'll make a note to add 3.3V to the physical layer phrase you point to.