ShellPkg: acpiview: Remove '-v' flag from allowed command line args

ShellPkg: acpiview: Remove '-v' flag from allowed command line args

According to the acpiview documentation, the -v flag enables verbose
output and it is set on default.

Moreover, the acpiview UEFI shell tool dumps the same output with
and without this flag set.

Therefore this patch removes the superfluous -v flag from allowed
command line parameters.

Signed-off-by: Krzysztof Koch <krzysztof.koch@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
Reviewed-by: Zhichao Gao <zhichao.gao@intel.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>