hw/arm/virt: Fix Manufacturer and Product Name in emulated SMBIOS mode

JIRA: https://issues.redhat.com/browse/RHEL-37543
Status: RHEL-only

In vm, when run 'dmidecode -t system', it outputs different Manufacturer and Product Name on x86_64 and aarch64 system. For example:

For aarch64 vm:
Manufacturer: QEMU
Product Name: KVM Virtual Machine

For x86_64 vm:
Manufacturer: Red Hat
Product Name: KVM

Fixing this issue by changing Manufacturer to ''Red Hat' and Product Name to 'KVM' on aarch64 platform. Thus the output is aligned on both x86_64 and aarch64 platform.

Signed-off-by: Shaoqin Huang shahuang@redhat.com