plat: imx: imx8qx: provide debug uart num as build param

1. This removes hardcoded iomux/clk/addr configuration for debug uart,
provides possibility (as a workaround, till that information isn't
provided via DT) to set this configuration during compile time via
IMX_DEBUG_UART build flag.

Also for Colibri i.MX8QXP different pinmux configuration is applied
for UART3, FLEXCAN2_RX/TX pads are muxed to ADMA_UART3_RX/TX.

2. Having DEBUG_CONSOLE enabled without enabling DEBUG_CONSOLE_A35
doesn't make sense (since UART pinmux/clock configuration is applied
for UART only when DEBUG_CONSOLE_A35 is enabled. Check similar commit
for i.MX8QM 98a69dfd4a("plat: imx: imx8qm: apply clk/pinmux
configuration for DEBUG_CONSOLE")).

Usage:
$ make PLAT=imx8qx IMX_DEBUG_UART=3 DEBUG_CONSOLE=1 bl31

Signed-off-by: Igor Opaniuk <igor.opaniuk@gmail.com>
Change-Id: I5d04939b2e8ee1a5f4b2f3c6241977d3c6e91760
diff --git a/plat/imx/imx8qx/include/platform_def.h b/plat/imx/imx8qx/include/platform_def.h
index 41475ff..b880e1b 100644
--- a/plat/imx/imx8qx/include/platform_def.h
+++ b/plat/imx/imx8qx/include/platform_def.h
@@ -38,7 +38,15 @@
 
 #define PLAT_GICD_BASE			0x51a00000
 #define PLAT_GICR_BASE			0x51b00000
+
+#if defined(IMX_USE_UART0)
 #define IMX_BOOT_UART_BASE		0x5a060000
+#elif defined(IMX_USE_UART3)
+#define IMX_BOOT_UART_BASE		0x5a090000
+#else
+#error "Provide proper UART configuration in IMX_DEBUG_UART"
+#endif
+
 #define IMX_BOOT_UART_BAUDRATE		115200
 #define IMX_BOOT_UART_CLK_IN_HZ		24000000
 #define PLAT_CRASH_UART_BASE		IMX_BOOT_UART_BASE
@@ -55,8 +63,6 @@
 
 /* non-secure u-boot base */
 #define PLAT_NS_IMAGE_OFFSET		0x80020000
-
-#define DEBUG_CONSOLE			0
-#define DEBUG_CONSOLE_A35		0
+#define DEBUG_CONSOLE_A35		DEBUG_CONSOLE
 
 #endif /* PLATFORM_DEF_H */