[TOP] Remove .o extension from VMM_MODNAME define

The VMM_MODNAME represents name of the module being compiled. It is
derived from filename of the source file containing VMM_DECLARE_MODULE()
macro. Currently, we were having .o extension in the VMM_MODNAME which
is not nice to have hence this patch removes .o extension from VMM_MODNAME.

Signed-off-by: Anup Patel <anup@brainfault.org>