Update the note on PAE to reflect support for PAE in GENERIC.

The PAE kernel now only determines if device drivers can avoid the use of
bounce buffers for DMA.

Reviewed by:	kib, emaste
Differential Revision:	https://reviews.freebsd.org/D28777

website/content/en/releases/13.0R/hardware.adoc

@@ -51,7 +51,7 @@ There are a wide variety of motherboards available for this architecture. Mother
 
 Symmetric multi-processor (SMP) systems are generally supported including multi-core and SMT.
 
-FreeBSD will take advantage of Physical Address Extensions (PAE) support on CPUs that support this feature. A kernel with the `PAE` feature enabled will detect memory above 4 gigabytes and allow it to be used by the system. This feature places constraints on the device drivers and other features of FreeBSD which may be used; consult the {{< manpage "pae" "4">}} manual page for more details.
+FreeBSD will take advantage of Physical Address Extensions (PAE) support on CPUs that support this feature. The default kernel supports memory up to 24 gigabytes, but device drivers will use bounce buffers to DMA buffers in memory above 4 gigabytes. A custom kernel with the `PAE` feature enabled will avoid the use of bounce buffers, but disables a few incompatible device drivers. This feature places constraints on other features of FreeBSD which may be used; consult the {{< manpage "pae" "4">}} manual page for more details.
 
 FreeBSD will generally run on i386-based laptops, desktops, and servers.
 Support for certain hardware features such as sound, graphics, wireless, and power management may vary