ARM: debug: add UART early console support for MSTAR SoCs

This adds the debug_ll uart for the PM UART found on armv7-based MStar
SoCs.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Acked-by: Daniel Palmer <daniel@thingy.jp>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Mohammed Billoo <mohammed.billoo@gmail.com>
Signed-off-by: Daniel Palmer <daniel@0x0f.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/Kconfig.debug

@@ -607,6 +607,14 @@ choice
 		  when u-boot hands over to the kernel, the system
 		  silently crashes, with no serial output at all.
 
+	config DEBUG_MSTARV7_PMUART
+		bool "Kernel low-level debugging messages via MSTARV7 PM UART"
+		depends on ARCH_MSTARV7
+		select DEBUG_UART_8250
+		help
+		  Say Y here if you want kernel low-level debugging support
+		  for MSTAR ARMv7-based platforms on PM UART.
+
 	config DEBUG_MT6589_UART0
 		bool "Mediatek mt6589 UART0"
 		depends on ARCH_MEDIATEK
@@ -1605,6 +1613,7 @@ config DEBUG_UART_PHYS
 	default 0x18000400 if DEBUG_BCM_HR2
 	default 0x18023000 if DEBUG_BCM_IPROC_UART3
 	default 0x1c090000 if DEBUG_VEXPRESS_UART0_RS1
+	default 0x1f221000 if DEBUG_MSTARV7_PMUART
 	default 0x20001000 if DEBUG_HIP01_UART
 	default 0x20060000 if DEBUG_RK29_UART0
 	default 0x20064000 if DEBUG_RK29_UART1 || DEBUG_RK3X_UART2
@@ -1722,6 +1731,7 @@ config DEBUG_UART_VIRT
 	default 0xf0100000 if DEBUG_DIGICOLOR_UA0
 	default 0xf01fb000 if DEBUG_NOMADIK_UART
 	default 0xf0201000 if DEBUG_BCM2835 || DEBUG_BCM2836
+	default 0xf0221000 if DEBUG_MSTARV7_PMUART
 	default 0xf1000300 if DEBUG_BCM_5301X
 	default 0xf1000400 if DEBUG_BCM_HR2
 	default 0xf1002000 if DEBUG_MT8127_UART0
@@ -1827,6 +1837,7 @@ config DEBUG_UART_8250_SHIFT
 	default 0 if DEBUG_FOOTBRIDGE_COM1 || ARCH_IOP32X || DEBUG_BCM_5301X || \
 		DEBUG_BCM_HR2 || DEBUG_OMAP7XXUART1 || DEBUG_OMAP7XXUART2 || \
 		DEBUG_OMAP7XXUART3
+	default 3 if DEBUG_MSTARV7_PMUART
 	default 2
 
 config DEBUG_UART_8250_WORD