arch: remove the ARCH_PHYS_ADDR_T_64BIT config symbol

Instead select the PHYS_ADDR_T_64BIT for 32-bit architectures that need a
64-bit phys_addr_t type directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: James Hogan <jhogan@kernel.org>
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d8..a3f0005 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -266,7 +266,7 @@
 	bool
 
 config PHYS_ADDR_T_64BIT
-	def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
+	def_bool 64BIT
 
 config BOUNCE
 	bool "Enable bounce buffers"