Revert "csu: test: explicitly add libm as build parameter"

This reverts commit 4f5890a0fb.

9ef1127008 is a proper fix for
the problem we tried to address.

Sponsored by:	Instituto de Pesquisas Eldorado (eldorado.org.br)

lib/csu/tests/dynamic/Makefile

@@ -2,11 +2,6 @@
 
 .PATH: ${.CURDIR:H}
 
-.if exists(./Makefile.${MACHINE_ARCH})
-.include "./Makefile.${MACHINE_ARCH}"
-.endif
-
-
 .include <src.opts.mk>
 MK_PIE=	no
 

lib/csu/tests/dynamic/Makefile.powerpcspe

@@ -1,11 +0,0 @@
-# $FreeBSD$
-
-# TODO: investigate and try a better fix on compiler side
-#
-# CSU tests build fails with '/usr/lib/libgcc_s.so: undefined reference to fma'
-# when built with LLVM 14, so '-lm' is being added explicitly here. Only
-# the powerpcspe target is affected and it may be linked to
-#       https://reviews.llvm.org/D77558
-
-LDFLAGS+=	-lm
-