include: configs: am62x_evm: Wrap distroboot with CONFIG_DISTRO_DEFAULTS

include: configs: am62x_evm: Wrap distroboot with CONFIG_DISTRO_DEFAULTS

Wrap the distro_boot options with CONFIG_DISTRO_DEFAULTS.

This is an intermediate step for us to switch over to
CONFIG_BOOTSTD_DEFAULTS and drop this section in follow on patches.

Reviewed-by: Tom Rini <trini@konsulko.com>
Tested-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>