libc: Move tf_printf and tf_snprintf to libc

Change their names to printf and snprintf. They are much smaller than
the previous versions we had, which makes them better suited for the
Trusted Firmware.

Change-Id: Ia872af91b7b967c47fce012eccecede7873a3daf
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/docs/psci-lib-integration-guide.rst b/docs/psci-lib-integration-guide.rst
index 47cbfcc..d86fc29 100644
--- a/docs/psci-lib-integration-guide.rst
+++ b/docs/psci-lib-integration-guide.rst
@@ -319,7 +319,7 @@
 below. The TF-A source tree provides implementations for all
 these functions but the EL3 Runtime Software may use its own implementation.
 
-**Functions : assert(), memcpy(), memset**
+**Functions : assert(), memcpy(), memset(), printf()**
 
 These must be implemented as described in ISO C Standard.
 
@@ -353,14 +353,6 @@
 This function will be called by the PSCI library on encountering a critical
 failure that cannot be recovered from. This function **must not** return.
 
-**Function : tf\_printf()**
-
-This is printf-compatible function, but unlike printf, it does not return any
-value. The TF-A source tree provides an implementation which
-is optimized for stack usage and supports only a subset of format specifiers.
-The details of the format specifiers supported can be found in the
-``tf_printf.c`` file in the TF-A source tree.
-
 CPU Context management API
 ~~~~~~~~~~~~~~~~~~~~~~~~~~