[X86][MC]Fix wrong action for encode movdir64b

Movdir64b is special for its mem operand, 67 prefex can not only modify its add size,
so it's mem base and index reg should be the same type as source reg, such as
movdir64b (%rdx), rcx, and could not be movdir64b (%edx), rcx.
Now llvm-mc can encode the asm 'movdir64b (%edx), rcx' but the result is the same as
'movdir64b (%edx), ecx', which offend users' intention, while gcc will object this
action and give a warning.
I add 3 new mem descriptions to let llvm-mc to report the same error.

Reviewed By: skan, craig.topper

Differential Revision: https://reviews.llvm.org/D145893