x86+Arm: drop (rename) __virt_to_maddr() / __maddr_to_virt()

x86+Arm: drop (rename) __virt_to_maddr() / __maddr_to_virt()

There's no use of them anymore except in the definitions of the non-
underscore-prefixed aliases.

On Arm convert the (renamed) inline function to a macro.

On x86 rename the inline functions, adjust the virt_to_maddr() #define,
and purge the maddr_to_virt() one, thus eliminating a bogus cast which
would have allowed the passing of a pointer type variable into
maddr_to_virt() to go silently.

No functional change intended.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Julien Grall <jgrall@amazon.com>