smart:cache.py: getPackages() matches name + arch

smart:cache.py: getPackages() matches name + arch

It only matched name ony in the past, for example:
smart install busybox (matched)
but:
smart install busybox@core2_64 (didn't match)

The installation is very slow when no match since it would seach all the
packages in the repo, and what we use mostly in oe-core is the second
case, so the installation is very slow when install COMPLEMENTARY
packages such as the task do_populate_sdk.

This patch makes it match both.

* Speed up
  MACHINE = "qemux86-64"
  - When multilib enabled:
    $ bitbake core-image-sato -cpopulate_sdk
    time: 6m5s -> 2m34s (Reduce 57% )

    $ bitbake core-image-minimal -cpopulate_sdk
    time: 2m1s -> 1m26s (Reduce 28% )

    $ bitbake core-image-sato-sdk
    time: 10m15s -> 7m12s (Reduce 29% )

  - When multilib NOT enabled:
    $ bitbake core-image-sato -cpopulate_sdk
    time: 4m25s -> 2m28s (Reduce 44% )

[YOCTO #8389]

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>