MdeModulePkg/BdsDxe: Also call PlatformBootManagerWaitCallback on 0

MdeModulePkg/BdsDxe: Also call PlatformBootManagerWaitCallback on 0

The existing loop is set to call PlatformBootManagerWaitCallback every
second except the last one. We believe this is a mistake as it prevents
the called code from performing timeout expiration tasks such as, for
instance, ensuring that the last segment of a progress bar is displayed
before continuing (which is a current issue for the RPi3 platform).

Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>