fix(rpi3): use correct define for GPIO reg_clr

Changed reg_clr to use the base address + RPI3_GPIO_GPCLR,
this corrects the reg_clr address.

Signed-off-by: Tushar Khandelwal <tushar.khandelwal@arm.com>
Signed-off-by: Abhi Singh <abhi.singh@arm.com>
Change-Id: I9ca50905efd4c640f143783c5a00676b246a2e26
1 file changed