OvmfPkg/QemuVideoDxe: sort [Sources*] sections in the INF file

OvmfPkg/QemuVideoDxe: sort [Sources*] sections in the INF file

This makes it easier to insert future source files. No functional changes.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Phil Dennis-Jordan <phil@philjordan.eu>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>