calao: use zImage on usb-a9263 and usb-a9g20 lpw

The board boot more fast with a zImage than a uImage
as the kernel will not have to be relocated during the decompression.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

configs/calao_usb_a9263_defconfig

@@ -11,3 +11,4 @@ BR2_TARGET_BAREBOX_BOARD_DEFCONFIG="usb_a9263"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/calao/usb-a9263/linux-3.4.4.config"
+BR2_LINUX_KERNEL_ZIMAGE=y

configs/calao_usb_a9g20_lpw_defconfig

@@ -12,3 +12,4 @@ BR2_TARGET_BAREBOX_BOARD_DEFCONFIG="usb_a9g20"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
 BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/calao/usb-a9g20-lpw/linux-3.4.4.config"
+BR2_LINUX_KERNEL_ZIMAGE=y