kernel: netdevices: fix typo for Aeonsemi AS21xxx description

Fix a typo on defining the PHY package kmod description that reference
phy-aeonsemi-as21x1x package instead of phy-aeonsemi-as21xxx.

Fixes: 08a616b ("generic: backport support for Aeonsemi AS21xxx PHY")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

Author: Ansuel

package/kernel/linux/modules/netdevices.mk

@@ -567,7 +567,7 @@ define KernelPackage/phy-aeonsemi-as21xxx
   AUTOLOAD:=$(call AutoLoad,18,as21xxx)
 endef
 
-define KernelPackage/phy-aeonsemi-as21x1x/description
+define KernelPackage/phy-aeonsemi-as21xxx/description
   Kernel modules for Aeonsemi AS21x1x 10G Ethernet PHY
 endef