m68k: fpsp040,ifpsp060: Remove meaningless EXTRA_LDFLAGS

These two Makefiles contain only built-in objects (i.e. obj-y), which
are collected by $(AR) into a thin-archive.

EXTRA_LDFLAGS is meaningless because $(LD) is not used here.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210331144336.25628-2-masahiroy@kernel.org


Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>