PIE is not supported by PRU and AVR backends for GCC.
This fixes LD errors when trying to link user programs with a
crosstool-NG toolchain:
/home/dinux/x-tools/avr/lib/gcc/avr/12.2.0/../../../../avr/bin/ld: -pie not supported
collect2: error: ld returned 1 exit status
Signed-off-by: Dimitar Dimitrov <dimitar@dinux.eu>