Power switching peripherial parts by MCU
If the display is running from the same power voltage as the micro, then there is no problem switching the ground side of the display's power.  Just make sure that all the micro ports connected to the display are either set to high impedance or driven high.

If the display communicates via a IIC bus, as many do, then switching the low side of the power actually makes things easier.  That way there will be no current thru the IIC pullups without you having to switch those separately.