hw/arm/boot: set CPTR_EL3.ESM and SCR_EL3.EnTP2 when booting Linux with EL3

hw/arm/boot: set CPTR_EL3.ESM and SCR_EL3.EnTP2 when booting Linux with EL3

According to the Linux kernel booting.rst [1], CPTR_EL3.ESM and
SCR_EL3.EnTP2 must be initialized to 1 when EL3 is present and FEAT_SME
is advertised. This has to be taken care of when QEMU boots directly
into the kernel (i.e., "-M virt,secure=on -cpu max -kernel Image").

Cc: qemu-stable@nongnu.org
Fixes: 78cb9776662a ("target/arm: Enable SME for -cpu max")
Link: [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/arm64/booting.rst?h=v6.0#n321
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Message-id: 20221003145641.1921467-1-jerome.forissier@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>