Update synopsys drivers to not rely on undefined overflow behaviour
Update synopsys drivers to not rely on undefined overflow behaviour

This consists of ensuring that the left operand of each shift is
unsigned when the operation might overflow into the sign bit.

Change-Id: I54560fe290e7dc52d364d0fe1c81a16f4c8d9a7b
Signed-off-by: Justin Chadwell <23868ac6bb803cbca62577fbb15c1a832c6e5215@arm.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware