ARM: 9040/1: use DEBUG_UART_PHYS and DEBUG_UART_VIRT for sti LL_UART

Update the sti platform LL_UART support to rely on
CONFIG_DEBUG_UART_PHYS and CONFIG_DEBUG_UART_VIRT from Kconfig

Signed-off-by: Alain Volmat <avolmat@me.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>