arm64: dts: amlogic: t7: khadas-vim4: fix board model name

Update the model property to "Khadas VIM4" to match the official
product branding and maintain consistency with other Khadas boards
(e.g., VIM1, VIM2, VIM3) in the kernel tree.

Signed-off-by: Nick Xie <nick@khadas.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20260306030756.2421841-1-nick@khadas.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>

[ upstream commit: 28e4a49a28b339b3d14564dd763d109799782687 ]

src/arm64/amlogic/amlogic-t7-a311d2-khadas-vim4.dts

diff --git a/src/arm64/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/src/arm64/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
index e7aff62..f4c9530 100644
--- a/src/arm64/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
+++ b/src/arm64/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
@@ -8,7 +8,7 @@
 #include "amlogic-t7.dtsi"
 
 / {
-	model = "Khadas vim4";
+	model = "Khadas VIM4";
 	compatible = "khadas,vim4", "amlogic,a311d2", "amlogic,t7";
 
 	aliases {