arm64: mm: Fix set_memory_valid() declaration

Clearly, set_memory_valid() has never been seen in the same room as its
declaration... Whilst the type mismatch is such that kexec probably
wasn't broken in practice, fix it to match the definition as it should.

Fixes: 9b0aa14e ("arm64: mm: add set_memory_valid()")
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/cacheflush.h

@@ -150,6 +150,6 @@ static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
 {
 }
 
-int set_memory_valid(unsigned long addr, unsigned long size, int enable);
+int set_memory_valid(unsigned long addr, int numpages, int enable);
 
 #endif