AVR unable to enter programming mode
Your low fuse register is 0xD7. That equals 0b1101 0111 in binary. 

Looking at the data sheet the lower 4 bits are responsible for the clock. This correlates to 

CKSEL3 = 0, CKSEL2 = 1, CKSEL1 = 1, CKSEL0 = 1.

From the data sheet this is not a valid setting, but it may be set to a low frequency crystal. The two similar valid settings are 0b0100 and 0b0101, they are both for a low frequency oscillator. Try replacing the 20MHz crystal with a 32.768kHz crystal. 

An expected frequency and actual frequency mismatch may result in the processor not starting. 

If that does not work, you may have to use parallel programming to recover the chip. Parallel programming does not require a working crystal and provides a clock externally. 

Here is a screen capture of the data sheet.