powerpc/mm: add ARCH_PKEY_BITS to Kconfig

The new config option specifies how many bits are in each PKEY.

Signed-off-by: Joey Gouly <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Nicholas Piggin <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Aneesh Kumar K.V <[email protected]>
Cc: Naveen N. Rao <[email protected]>
Cc: [email protected]
Acked-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: jgouly

arch/powerpc/Kconfig

@@ -1026,6 +1026,10 @@ config PPC_MEM_KEYS
 
 	  If unsure, say y.
 
+config ARCH_PKEY_BITS
+	int
+	default 5
+
 config PPC_SECURE_BOOT
 	prompt "Enable secure boot support"
 	bool