Platform:corstone1000: Add common platform logger

platform_log defines log messages macros to be used by the platform code
It allows defining the module name to be added at the beginning of the log
message.
Based on build type PLAT_LOG_LEVEL is defined.
In case of Debug/RelWithDebInfo PLAT_LOG_LEVEL is defined to Debug level
else it is defined to OFF.

usage in source file:
...
INFO("msg");
ERROR("msg");
WARN("msg");
VERBOSE("msg");
DEBUG("msg");
...

Signed-off-by: Mohamed Omar Asaker <mohamed.omarasaker@arm.com>
Change-Id: Id730d3de18dcf2bbf37ed974a9403235fcb79f4c