binman: Add nxp_imx8mcst etype for i.MX8M flash.bin signing

Add new binman etype which allows signing both the SPL and fitImage sections
of i.MX8M flash.bin using CST. There are multiple DT properties which govern
the signing process, nxp,loader-address is the only mandatory one which sets
the SPL signature start address without the imx8mimage header, this should be
SPL text base. The key material can be configured using optional DT properties
nxp,srk-table, nxp,csf-crt, nxp,img-crt, all of which default the key material
names generated by CST tool scripts. The nxp,unlock property can be used to
unlock CAAM access in SPL section.

Reviewed-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Marek Vasut <marex@denx.de>
4 files changed