drivers/gicv3: also shift eSPI register offset in GICD_OFFSET_64()
drivers/gicv3: also shift eSPI register offset in GICD_OFFSET_64()

ESPI register offset should also be shifted right by REG##R_SHIFT to
keep consistent.

It is not a functional issue, for GICD_OFFSET_64() is only used for
GICD_IROUTER<E>, and IROUTER_SHIFT is 0.

Signed-off-by: Heyi Guo <554902d6d74fca466aa06b42f6ec0849d7c72a90@linux.alibaba.com>
Change-Id: I76eee5c50e4300890e78e80bddde135ce88daa2d

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