LoongArch: Further refine the condition to enable static PIE

Before GCC r13-2728, it would produce a normal dynamic-linked executable
with -static-pie.  I mistakely believed it would produce a static-linked
executable, so failed to detect the breakage.  Then with Binutils 2.40
and (vanilla) GCC 12, libc_cv_static_pie_on_loongarch is mistakenly
enabled and cause a building failure with "undefined reference to
_DYNAMIC".

Fix the issue by disabling static PIE if -static-pie creates something
with a INTERP header.