configs/ti_am62x_sk: bump Linux to version 6.12.43

The Cadence QSPI driver is broken in version 6.12.36. It was fixed by a
subsequent patch:

https://lore.kernel.org/all/20250730093234.216392179@linuxfoundation.org/

Which was later backported to the 6.12 stable branch.

Bump the kernel version to the latest 6.12.x stable version to fix QSPI
support.

Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>

board/ti/am62x-sk/patches/linux/linux.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256  4a168aed2de5a81aadd90ba2b153860a98d99bfc34651936e17f18e54f01ba8c  linux-6.12.36.tar.xz
+sha256  0fcbbbbcd456e87bbbfc8bf37af541fda62ccfcce76903503424fd101ef7bdee  linux-6.12.43.tar.xz

configs/ti_am62x_sk_defconfig

@@ -8,7 +8,7 @@ BR2_ROOTFS_POST_BUILD_SCRIPT_ARGS="-c ttyS2,115200n8 -d k3-am625-sk.dtb -l am62x
 BR2_ROOTFS_POST_IMAGE_SCRIPT_ARGS="-c board/ti/am62x-sk/genimage.cfg"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="6.12.36"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="6.12.43"
 BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
 BR2_LINUX_KERNEL_DTS_SUPPORT=y
 BR2_LINUX_KERNEL_INTREE_DTS_NAME="ti/k3-am625-sk"