install: Replace scripts/output-format.sed with objdump -f [BZ #26559]

GNU ld and gold have supported --print-output-format since 2011. glibc
requires binutils>=2.25 (2015), so if LD is GNU ld or gold, we can
assume the option is supported.

lld is by default a cross linker supporting multiple targets. It auto
detects the file format and does not need OUTPUT_FORMAT. It does not
support --print-output-format.

By parsing objdump -f, we can support all the three linkers.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>