sys/octeon: add em to GENERIC and RAMDISK kernels

tech@,

I'd like em driver to both GENERIC and RAMDISK kernel.

I almost sure that octeon device with e1000 do not exists, but it is very
useful for emulation in QEMU for example.

Implement Octeon's NIC is tricky, but reuse e1000 seems a nice shortcut.

Ok?

Index: sys/arch/octeon/conf/GENERIC
===================================================================
RCS file: /home/cvs/src/sys/arch/octeon/conf/GENERIC,v
diff -u -p -r1.62 GENERIC
--- sys/arch/octeon/conf/GENERIC	16 May 2025 16:35:12 -0000	1.62
+++ sys/arch/octeon/conf/GENERIC	19 Jun 2026 11:45:04 -0000
@@ -51,6 +51,9 @@ pci*		at pcibus?
 ppb*		at pci?		# PCI-PCI bridges
 pci*		at ppb?
 
+# PCI Ethernet
+em*		at pci?		# Intel Pro/1000 ethernet
+
 octsmi*		at fdt?		# MDIO controller
 com*		at fdt_octeon?
 octcib*		at fdt?		# Interrupt controller
Index: sys/arch/octeon/conf/RAMDISK
===================================================================
RCS file: /home/cvs/src/sys/arch/octeon/conf/RAMDISK,v
diff -u -p -r1.47 RAMDISK
--- sys/arch/octeon/conf/RAMDISK	11 Jan 2023 03:28:42 -0000	1.47
+++ sys/arch/octeon/conf/RAMDISK	19 Jun 2026 12:53:43 -0000
@@ -49,6 +49,9 @@ pci*		at pcibus?
 ppb*		at pci?
 pci*		at ppb?
 
+# PCI Ethernet
+em*		at pci?		# Intel Pro/1000 ethernet
+
 octsmi*		at fdt?		# MDIO controller
 com*		at fdt_octeon?
 octcib*		at fdt?		# Interrupt controller

-- 
wbr, Kirill