Fix: incorrect platform path lowercase conversion

TS has a naming convention which requires directory names being
lowercase. AddPlatform.cmake::add_platform() enforces this and converts
the path constructed from TS_PLATFORM variable to lower case. This was
done incorrectly as TS_ROOT was converted to. This made it impossible to
build TS from any location which had capital letters in any directory
name above TS_ROOT.
This change fixes the conversion and limits the effect to paths under
TS_ROOT.

Signed-off-by: Vishnu Banavath <vishnu.banavath@arm.com>
Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Signed-off-by: György Szing <gyorgy.szing@arm.com>
Change-Id: Icf14b6a78d01878e7a4c9b53f3ec429944e16225
1 file changed