Fix libgmp.a on powerpc, which needs the PIC asm, because OpenBSD uses
PIE position-independent executables.  powerpc and powerpc64 define
PIC_ALWAYS to `yes', but the quotes on `PIC_ALWAYS' broke the macro
expansion.  This fix prevents text relocation errors on powerpc when
ld.lld links gdb >= 8 with libgmp.a.

ld: error: can't create dynamic relocation R_PPC_ADDR16_HA against local symbol in readonly segment; recompile object files with -fPIC or pass '-Wl,-z,notext' to allow text relocations in the output
>>> defined in /usr/local/lib/libgmp.a(invert_limb.o)
>>> referenced by tmp-invert_limb.s
>>>               invert_limb.o:(__gmpn_invert_limb) in archive /usr/local/lib/libgmp.a

Index: mpn/asm-defs.m4
--- mpn/asm-defs.m4.orig
+++ mpn/asm-defs.m4
@@ -1051,7 +1051,7 @@ dnl  Normally PIC is defined (or not) by libtool, but 
 dnl  systems which are always PIC.  PIC_ALWAYS established in config.m4
 dnl  identifies these for us.
 
-ifelse(`PIC_ALWAYS',`yes',`define(`PIC')')
+ifelse(PIC_ALWAYS,`yes',`define(`PIC')')
 
 
 dnl  Various possible defines passed from the Makefile that are to be tested
