xtensa: remove ZONE_DMA

ZONE_DMA is intended for magic < 32-bit pools (usually ISA DMA), which
isn't required on xtensa. Move all the non-highmem memory into
ZONE_NORMAL instead to match other architectures.

Signed-off-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Max Filippov <[e-mail]>

arch/xtensa/Kconfig

···
 # SPDX-License-Identifier: GPL-2.0
-config ZONE_DMA
-	def_bool y
-
 config XTENSA
 	def_bool y
 	select ARCH_HAS_SG_CHAIN

arch/xtensa/mm/init.c

···
 {
 	/* All pages are DMA-able, so we put them all in the DMA zone. */
 	unsigned long zones_size[MAX_NR_ZONES] = {
-		[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET,
+		[ZONE_NORMAL] = max_low_pfn - ARCH_PFN_OFFSET,
 #ifdef CONFIG_HIGHMEM
 		[ZONE_HIGHMEM] = max_pfn - max_low_pfn,
 #endif