at91: remove redundant AT91FAMILY definition in board config file

Now the AT91FAMILY is already defined in the at91 SoC header. The at91
board config file will include the SoC header file.

So we can remove the redundant AT91FAMILY definition in at91 board
config files.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
[rebase patch]
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
9 files changed