powerpc/64: drop redundant defination of spin_until_cond

linux/processor.h has exactly same defination for spin_until_cond.
Drop the redundant defination in asm/processor.h

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1fff2054e5dfc00329804dbd3f2a91667c9a8aff.1623438544.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/processor.h

@@ -347,17 +347,6 @@ static inline unsigned long __pack_fe01(unsigned int fpmode)
 
 #define spin_end()	HMT_medium()
 
-#define spin_until_cond(cond)					\
-do {								\
-	if (unlikely(!(cond))) {				\
-		spin_begin();					\
-		do {						\
-			spin_cpu_relax();			\
-		} while (!(cond));				\
-		spin_end();					\
-	}							\
-} while (0)
-
 #endif
 
 /* Check that a certain kernel stack pointer is valid in task_struct p */