MIPS: math-emu: Add z argument macros

Introduce macros for handling the "z" argument to maddf & msubf, making
its handling consistent with that of the "x" & "y" arguments rather than
open-coding equivalents.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13156/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/math-emu/ieee754dp.h

@@ -60,6 +60,7 @@ static inline int ieee754dp_finite(union ieee754dp x)
 	while ((m >> DP_FBITS) == 0) { m <<= 1; e--; }
 #define DPDNORMX	DPDNORMx(xm, xe)
 #define DPDNORMY	DPDNORMx(ym, ye)
+#define DPDNORMZ	DPDNORMx(zm, ze)
 
 static inline union ieee754dp builddp(int s, int bx, u64 m)
 {