Dump platform-defined regs in crash reporting

It is up to the platform to implement the new plat_crash_print_regs macro to
report all relevant platform registers helpful for troubleshooting.

plat_crash_print_regs merges or calls previously defined plat_print_gic_regs
and plat_print_interconnect_regs macros for each existing platforms.

NOTE: THIS COMMIT REQUIRES ALL PLATFORMS THAT ENABLE THE `CRASH_REPORTING`
BUILD FLAG TO MIGRATE TO USE THE NEW `plat_crash_print_regs()` MACRO. BY
DEFAULT, `CRASH_REPORTING` IS ENABLED IN DEBUG BUILDS FOR ALL PLATFORMS.

Fixes: arm-software/tf-issues#373

Signed-off-by: Gerald Lejeune <gerald.lejeune@st.com>
diff --git a/docs/porting-guide.md b/docs/porting-guide.md
index 5e14823..0d713c4 100644
--- a/docs/porting-guide.md
+++ b/docs/porting-guide.md
@@ -489,20 +489,15 @@
 the following macro defined. In the ARM development platforms, this file is
 found in `plat/arm/board/<plat_name>/include/plat_macros.S`.
 
-*   **Macro : plat_print_gic_regs**
+*   **Macro : plat_crash_print_regs**
 
-    This macro allows the crash reporting routine to print GIC registers
-    in case of an unhandled exception in BL31. This aids in debugging and
-    this macro can be defined to be empty in case GIC register reporting is
-    not desired.
-
-*   **Macro : plat_print_interconnect_regs**
-
-    This macro allows the crash reporting routine to print interconnect
+    This macro allows the crash reporting routine to print relevant platform
     registers in case of an unhandled exception in BL31. This aids in debugging
-    and this macro can be defined to be empty in case interconnect register
-    reporting is not desired. In ARM standard platforms, the CCI snoop
-    control registers are reported.
+    and this macro can be defined to be empty in case register reporting is not
+    desired.
+
+    For instance, GIC or interconnect registers may be helpful for
+    troubleshooting.
 
 
 2.2 Handling Reset