gemini: add generic subtarget

Same game as for 853e4dd3062df7cb5704b15d6af6730e3194b571. Add generic
to the filenames.

Signed-off-by: Christian Marangi <[email protected]>

target/linux/gemini/Makefile

@@ -9,6 +9,7 @@ BOARD:=gemini
 BOARDNAME:=Cortina Systems CS351x
 FEATURES:=squashfs pci rtc usb dt gpio display ext4 rootfs-part boot-part
 CPU_TYPE:=fa526
+SUBTARGETS:=generic
 
 KERNEL_PATCHVER:=5.15
 

target/linux/gemini/generic/target.mk

@@ -0,0 +1 @@
+BOARDNAME:=Generic