ARM: aspeed: Kconfig: Fix indentation

The convention for indentation seems to be a single tab. Help text is
further indented by an additional two whitespaces. Fix the lines that
violate these rules.
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20220523060532.7864-1-juergh@canonical.com
Link: https://lore.kernel.org/r/20220928025926.2592030-1-joel@jms.id.au'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>