configs/aarch64_efi_defconfig: bump kernel version

Bump Linux kernel version to 5.15.4.

We enlarge the boot partition to follow the kernel image size increase and
update the documentation.

Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Reviewed-by: Dick Olsson <hi@senzilla.io>
Cc: Erico Nunes <nunes.erico@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

board/aarch64-efi/genimage-efi.cfg

@@ -8,7 +8,7 @@ image efi-part.vfat {
 		}
 	}
 
-	size = 32M
+	size = 64M
 }
 
 image disk.img {

board/aarch64-efi/readme.txt

@@ -45,7 +45,7 @@ the instructions in [3], with qemu_arm64_defconfig.
 
 This should give you a nor_flash.bin, which you can use with qemu as an
 alternative to QEMU_EFI.fd. You will also need to change the machine
-specification to "-M virt,secure" on qemu command line, to enable TrustZone
+specification to "-M virt,secure=on" on qemu command line, to enable TrustZone
 support, and you will need to increase the memory with "-m 1024".
 
 [1]: https://github.com/ARM-software/ebbr

configs/aarch64_efi_defconfig

@@ -22,13 +22,13 @@ BR2_TARGET_ROOTFS_EXT2_SIZE="200M"
 BR2_ROOTFS_POST_IMAGE_SCRIPT="board/aarch64-efi/post-image.sh support/scripts/genimage.sh"
 BR2_ROOTFS_POST_SCRIPT_ARGS="-c board/aarch64-efi/genimage-efi.cfg"
 
-# Linux headers same as kernel, a 5.11 series
-BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_11=y
+# Linux headers same as kernel, a 5.15 series
+BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_5_15=y
 
 # Kernel
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.11.16"
+BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.15.4"
 BR2_LINUX_KERNEL_USE_ARCH_DEFAULT_CONFIG=y
 BR2_LINUX_KERNEL_NEEDS_HOST_OPENSSL=y