mgb.4, muge.4: Use standard HARDWARE introduction

Release notes are generated using this text.

I used "interfaces" not "adapters" in these pages as the listed devices
are the controller ICs, not end-user projects.

Reviewed by:	ziaee
Sponsored by:	The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D53846

share/man/man4/mgb.4

@@ -49,7 +49,7 @@ For more information on configuring this device, see
 .Sh HARDWARE
 The
 .Nm
-driver supports:
+driver supports Microchip PCIe Gigabit Ethernet interfaces, including:
 .Pp
 .Bl -bullet -compact
 .It

share/man/man4/muge.4

@@ -44,7 +44,7 @@ For more information on configuring this device, see
 .Sh HARDWARE
 The
 .Nm
-driver supports:
+driver supports Microchip USB Gigabit Ethernet interfaces, including:
 .Pp
 .Bl -bullet -compact
 .It