ARM:AM33XX: Replace CONFIG_AM335X with CONFIG_AM33XX

This patch is added to replace CONFIG_AM335X symbol
with CONFIG_AM333XX for AM33XX platforms.

Signed-off-by: Chandan Nath <chandan.nath@ti.com>
Signed-off-by: Tom Rini <trini@ti.com>
Tested-by: Thomas Weber <weber@corscience.de>