AT91SAM9*: Change kernel address in dataflash to match u-boot's size

AT91SAM9*: Change kernel address in dataflash to match u-boot's size

On at91sam platforms, u-boot grew larger than the allocated size in
dataflash, the layout was:
bootstrap  0x00000000
ubootenv   0x00004200
uboot      0x00008400
kernel     0x00042000
fs         0x00252000

u-boot with the defconfig doesn't seem to fit in 0x42000 - 0x8400 =
0x39C00 bytes anymore.

Now, the layout is:
bootstrap  0x00000000
ubootenv   0x00004200
uboot      0x00008400
kernel     0x00084000
fs         0x00294000

Signed-off-by: Alexandre Belloni <alexandre.belloni@piout.net>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>