msm: ep-pcie: Give BAR0 and BAR2 the right size

dev->mmio_res_size is not initialized, so during D3_COLD -> D0 transition,
when the driver re-initializes the BAR registers, they are overwritten by
dev->mmio_res_size. Fix it by calculating the size of MMIO resource and
using the calculated size in ep_pcie_bar_init().

Change-Id: Ifad54ed1ffbcf205e89f9ab6d54e54350d5e7788
Signed-off-by: Can Guo <cang@codeaurora.org>