configs: enable DEFERRED_STRUCT_PAGE_INIT for fast boot

Deferred struct_page init can same more boot time, especially for large
memory instance. In my local test with 2C312GB VM, it decreases from
2.389s to 0.138s.
Please note that this has a potential performance impact on processes
running early in the lifetime of the system until these kthreads finish
the initialisation.
Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>

config-4.19.y-x86_64

@@ -913,7 +913,7 @@ CONFIG_ZSMALLOC=m
 # CONFIG_PGTABLE_MAPPING is not set
 # CONFIG_ZSMALLOC_STAT is not set
 CONFIG_GENERIC_EARLY_IOREMAP=y
-# CONFIG_DEFERRED_STRUCT_PAGE_INIT is not set
+CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
 # CONFIG_IDLE_PAGE_TRACKING is not set
 CONFIG_ARCH_HAS_ZONE_DEVICE=y
 CONFIG_ZONE_DEVICE=y

config-4.19.y-x86_64-debug

@@ -913,7 +913,7 @@ CONFIG_ZSMALLOC=m
 # CONFIG_PGTABLE_MAPPING is not set
 # CONFIG_ZSMALLOC_STAT is not set
 CONFIG_GENERIC_EARLY_IOREMAP=y
-# CONFIG_DEFERRED_STRUCT_PAGE_INIT is not set
+CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
 # CONFIG_IDLE_PAGE_TRACKING is not set
 CONFIG_ARCH_HAS_ZONE_DEVICE=y
 CONFIG_ZONE_DEVICE=y