This commit migrates the bootloader build from Raspberry Pi 4 board
package to a dedicated bootloader defconfig. The idea is to set up
dedicated wokflows for building bootloaders, which change rarely,
streamlining the Infix image builds.
A dedicated workflow, or job in an existing workflow, can then do
the composition to minimal SD-card images useful for starting up
Infix on boards where SD-card is the primary boot source.
Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
Joachim Wiberg
ebf4157e2c