cpufrequtils: handle i386 -fPIC case

One problem with the cpuid instruction is that it uses %ebx which,
when code is compiled as PIC for i386, is used as the PIC base register.
This patch tries to handle this case by replacing the second register (%1)
constraint with "=r", i.e. any (other) register, and swapping %ebx and %1
around the cpuid instruction.

This patch could use a test, preferably on real i686 hardware.
At least it needs some review and perhaps inspection of the generated
assembler output.

The idea and reasoning was taken from this comment:
http://gcc.gnu.org/ml/gcc-patches/2007-09/msg00324.html

srcpkgs/cpufrequtils/patches/pic-i386.patch

@@ -0,0 +1,33 @@
+--- utils/cpuid.h	2010-07-05 17:43:17.000000000 +0200
++++ utils/cpuid.h	2016-10-13 22:31:26.988374329 +0200
+@@ -1,6 +1,21 @@
+ #ifndef _CPUFREQ_CPUID_H
+ #define _CPUFREQ_CPUID_H
+ 
++#if defined(__i386__) && defined(__PIC__)
++static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
++				unsigned int *ecx, unsigned int *edx)
++{
++	/* ecx is often an input as well as an output. */
++	asm volatile("xchgl\t%%ebx, %1\n\t" \
++	      "cpuid\n\t" \
++	      "xchgl\t%%ebx, %1"
++	    : "=a" (*eax),
++	      "=r" (*ebx),
++	      "=c" (*ecx),
++	      "=d" (*edx)
++	    : "0" (*eax), "2" (*ecx));
++}
++#else
+ static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
+ 				unsigned int *ecx, unsigned int *edx)
+ {
+@@ -12,6 +27,8 @@
+ 	      "=d" (*edx)
+ 	    : "0" (*eax), "2" (*ecx));
+ }
++#endif
++
+ static inline void cpuid(unsigned int op,
+ 			 unsigned int *eax, unsigned int *ebx,
+ 			 unsigned int *ecx, unsigned int *edx)

srcpkgs/cpufrequtils/template

@@ -1,14 +1,13 @@
 # Template file for 'cpufrequtils'
 pkgname=cpufrequtils
 version=008
-revision=10
+revision=11
 short_desc="Userspace tools for the Linux kernel cpufreq subsystem"
 homepage="ftp://ftp.archlinux.org/other/cpufrequtils/"
 license="GPL-2"
 maintainer="Juan RP <xtraeme@voidlinux.eu>"
-distfiles="https://www.kernel.org/pub/linux/utils/kernel/cpufreq/${pkgname}-${version}.tar.xz"
+distfiles="${KERNEL_SITE}/utils/kernel/cpufreq/${pkgname}-${version}.tar.xz"
 checksum=a2149db551f83112209b1a8e79bd50d386979bbf64edbc69126f4e0b4f0a4cab
-nopie=yes
 
 only_for_archs="i686 i686-musl x86_64 x86_64-musl"
 
@@ -29,7 +28,7 @@ libcpufreq_package() {
 libcpufreq-devel_package() {
 	conflicts="libcpupower-devel>=0"
 	depends="libcpufreq>=${version}_${revision}"
-	short_desc="libcpufreq - development tools"
+	short_desc="Library for the kernel cpufreq subsystem - development tools"
 	pkg_install() {
 		vmove usr/include
 		vmove "usr/lib/*.so"