ARM: aspeed: Don't select SRAM

The ASPEED devices have SRAM, but don't require it for basic function
(or any function; there's no known users of the driver).

Fixes: 8c2ed9bc ("arm: Add Aspeed machine")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://patch.msgid.link/20250115103942.421429-1-joel@jms.id.au


Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>