ARM: at91: remove redundant dependency

This removes the "depends on SOC_SAM_V7" statement
in a Kconfig section that's under an "if SOC_SAM_V7"
condition (same parameter).

Signed-off-by: Yanis Moreno <yanis.moreno63@gmail.com>
Reviewed-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Olof Johansson <olof@lixom.net>