common.mak: Remove no-pie support check

The command line options -fno-pie/-no-pie are required by boot loaders
as they have strict layout requirements. A check was implemented using
-dumpspecs to evaluate the compiler support as older compilers didn't
support the no-pie command line options.
However, -dumpspecs is a GCC specific option and the check will
therefore always fail for Clang. The objective is to enable Clang
compilation support for s390-tools in the long-run.

Since support for -fno-pie/-no-pie in GCC was introduced 2015 with
version 6.1.0 and in Clang 2010 with version 3.0.0, general support can
be assumed.

Simply remove the support check and get rid of another obstacle that's
in the way for full Clang support.

Suggested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

common.mak

@@ -340,13 +340,8 @@ endif
 export INSTALL CFLAGS CXXFLAGS \
        LDFLAGS CPPFLAGS ALL_CFLAGS ALL_CXXFLAGS ALL_LDFLAGS ALL_CPPFLAGS
 
-ifneq ($(shell $(CC_SILENT) -dumpspecs 2>/dev/null | grep -e '[^f]no-pie'),)
-	NO_PIE_CFLAGS := -fno-pie
-	NO_PIE_LDFLAGS := -no-pie
-else
-	NO_PIE_CFLAGS :=
-	NO_PIE_LDFLAGS :=
-endif
+NO_PIE_CFLAGS := -fno-pie
+NO_PIE_LDFLAGS := -no-pie
 
 # Overwrite implicit makefile rules for having nice compile output
 %.o: %.c