powerpc/8xx: Allow pinning IMMR TLB when using early debug console

CONFIG_EARLY_DEBUG_CPM requires IMMR area TLB to be pinned
otherwise it doesn't survive MMU_init, and the boot fails.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/Kconfig

@@ -1143,7 +1143,7 @@ config PIN_TLB_DATA
 
 config PIN_TLB_IMMR
 	bool "Pinned TLB for IMMR"
-	depends on PIN_TLB
+	depends on PIN_TLB || PPC_EARLY_DEBUG_CPM
 	default y
 
 config PIN_TLB_TEXT