Integrate newlib into opteesp environment

Use newlib external component in opteesp targeted builds along the
necessary compiler and linker options. Also adding/modifying the source
files for startup, heap handling and trace features. The sp.ld.S file
is based on ta/arch/arm/ta.ld.S from optee_os
6be0dbcaa11394a2ad5a46ac77e2f76e31a41722.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: Ie9f3e8f0fb755bb88cc33feffda86fbbbf3c7fce
12 files changed