ARM: debug: remove references in DEBUG_UART_8250_SHIFT to removed configs

Commit 67d3928c3df5 ("ARM: omap1: remove unused board files") removes
configs DEBUG_OMAP7XXUART{1,2,3}.

The config DEBUG_UART_8250_SHIFT still refers to those removed configs.

Remove those obsolete references.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/Kconfig.debug

@@ -1782,8 +1782,7 @@ config DEBUG_UART_8250_SHIFT
 	int "Register offset shift for the 8250 debug UART"
 	depends on DEBUG_LL_UART_8250 || DEBUG_UART_8250
 	default 0 if DEBUG_FOOTBRIDGE_COM1 || DEBUG_BCM_5301X || \
-		DEBUG_BCM_HR2 || DEBUG_OMAP7XXUART1 || DEBUG_OMAP7XXUART2 || \
-		DEBUG_OMAP7XXUART3
+		DEBUG_BCM_HR2
 	default 3 if DEBUG_MSTARV7_PMUART
 	default 2