mediatek: move MT8173 VPU FW to subfolder

Currently vpu_d.bin and vpu_p.bin are at the root of
linux-firmware git tree, it's not appropriate so we move
them to subfolder mediatek/mt8173 and create a symbolic link
to be compatible with older kernels

Release Version: 1.1.4
Signed-off-by: Rui Wang <gtk_ruiwang@mediatek.com>

WHENCE

@@ -4450,8 +4450,10 @@ Licence: Redistributable. See LICENCE.Marvell for details.
 
 Driver: mtk-vpu - Mediatek VPU video processing unit driver
 
-File: vpu_d.bin
-File: vpu_p.bin
+File: mediatek/mt8173/vpu_d.bin
+File: mediatek/mt8173/vpu_p.bin
+Link: vpu_d.bin -> mediatek/mt8173/vpu_d.bin
+Link: vpu_p.bin -> mediatek/mt8173/vpu_p.bin
 
 Licence: Redistributable.
 

vpu_d.bin

+mediatek/mt8173/vpu_d.bin
\ No newline at end of file

vpu_p.bin

+mediatek/mt8173/vpu_p.bin
\ No newline at end of file