xtensa: add FORCE_MAX_ZONEORDER to Kconfig

Make maximal memory allocation order configurable, so that drivers could
allocate huge buffers when they need to.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/Kconfig

@@ -398,6 +398,20 @@ config SIMDISK1_FILENAME
 
 source "mm/Kconfig"
 
+config FORCE_MAX_ZONEORDER
+	int "Maximum zone order"
+	default "11"
+	help
+	  The kernel memory allocator divides physically contiguous memory
+	  blocks into "zones", where each zone is a power of two number of
+	  pages.  This option selects the largest power of two that the kernel
+	  keeps in the memory allocator.  If you need to allocate very large
+	  blocks of physically contiguous memory, then you may need to
+	  increase this value.
+
+	  This config option is actually maximum order plus one. For example,
+	  a value of 11 means that the largest free memory block is 2^10 pages.
+
 source "drivers/pcmcia/Kconfig"
 
 source "drivers/pci/hotplug/Kconfig"