[openwrt/openwrt] airoha: fix imagebuilder generation by introducing generic target

[LEDE Commits]

ansuel pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/dbce336539a862c1ef01b69a8b7b137018c3c281

commit dbce336539a862c1ef01b69a8b7b137018c3c281
Author: Nick Hainke <vincent at systemli.org>
AuthorDate: Sun Sep 11 21:53:20 2022 +0200

    airoha: fix imagebuilder generation by introducing generic target
    
    The generic imagebuilder does not have a generic in the name, although
    this is the default naming scheme. Apply the same fix as for the octeon
    target. Thanks to @dangowrt for reporting that the same issues applies
    also for the airoha target.
    
    Before the fix:
    openwrt-imagebuilder-airoha.Linux-x86_64.tar.xz
    
    After:
    openwrt-imagebuilder-airoha-generic.Linux-x86_64.tar.xz
    
    Signed-off-by: Nick Hainke <vincent at systemli.org>
---
 target/linux/airoha/generic/target.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/linux/airoha/generic/target.mk b/target/linux/airoha/generic/target.mk
new file mode 100644
index 0000000000..f5cb1fb19b
--- /dev/null
+++ b/target/linux/airoha/generic/target.mk
@@ -0,0 +1 @@
+BOARDNAME:=Generic