x86/mm: Drop CONFIG_SWIOTLB for PAE

Since kernels with and without CONFIG_X86_PAE are now limited
to the low 4GB of physical address space, there is no need to
use swiotlb any more, so stop selecting this.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250226213714.4040853-7-arnd@kernel.org

arch/x86/Kconfig

@@ -1462,7 +1462,6 @@ config X86_PAE
 	bool "PAE (Physical Address Extension) Support"
 	depends on X86_32 && X86_HAVE_PAE
 	select PHYS_ADDR_T_64BIT
-	select SWIOTLB
 	help
 	  PAE is required for NX support, and furthermore enables
 	  larger swapspace support for non-overcommit purposes. It