plat: xilinx: Use fno-jump-tables flag in CPPFLAGS
plat: xilinx: Use fno-jump-tables flag in CPPFLAGS

From GCC-9 implementation of switch case was generated through jump tables,
because of which we are seeing 1MB increase in rodata section. To reduce
the size we are recommending to use fno-jump-tables.

Signed-off-by: Venkatesh Yadav Abbarapu <e03c3614aac6f2d43431bff477d9e81e834877b6@xilinx.com>
Signed-off-by: Michal Simek <b20e59da6aeb5cea6c82b021069d69f63616c55d@xilinx.com>
Change-Id: I069733610809b8299fbf641f0ae35b359a8afd69

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