arm: qemu: fix update_info declaration

arm: qemu: fix update_info declaration

Add a missing comma in the update_info structure declaration.

This fixes the following build error when building with
EFI_RUNTIME_UPDATE_CAPSULE or EFI_CAPSULE_ON_DISK:

  board/emulation/qemu-arm/qemu-arm.c:52:9: error: request for member ‘images’ in something not a structure or union

Fixes: cccea18813c4 ("efi_loader: add the number of image entries in efi_capsule_update_info")
Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Cc: Masahisa Kojima <masahisa.kojima@linaro.org>
Cc: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Cc: Tom Rini <trini@konsulko.com>