feat(intel): add macro to switch between different UART PORT

HSD #1509626040:
This patch is to add the flexibility for BL2 and BL31
to choose different UART output port at platform_def.h
using parameter PLAT_INTEL_UART_BASE

This patch also fixing the plat_helpers.S where the
UART BASE is hardcoded to PLAT_UART0_BASE. It is then
switched to CRASH_CONSOLE_BASE.

Signed-off-by: Boon Khai Ng <boon.khai.ng@intel.com>
Change-Id: Iccfa7ec64e4955b531905778be4da803045d3c8f
diff --git a/plat/intel/soc/n5x/bl31_plat_setup.c b/plat/intel/soc/n5x/bl31_plat_setup.c
index 2a8daa6..5ca1a71 100644
--- a/plat/intel/soc/n5x/bl31_plat_setup.c
+++ b/plat/intel/soc/n5x/bl31_plat_setup.c
@@ -42,8 +42,8 @@
 
 	mmio_write_64(PLAT_SEC_ENTRY, 0);
 
-	console_16550_register(PLAT_UART0_BASE, PLAT_UART_CLOCK, PLAT_BAUDRATE,
-		&console);
+	console_16550_register(PLAT_INTEL_UART_BASE, PLAT_UART_CLOCK,
+		PLAT_BAUDRATE, &console);
 	/*
 	 * Check params passed from BL31 should not be NULL,
 	 */