Updated the build script using ./build/build_xxx.sh

Updated the build script using ./build/build_xxx.sh

1. Switched to Mobile 3.0 as the default target for build_mobile.sh

This patch changes the default target to 3.0 from 2.4.
Also we uses the arm64-wayland profile which is main target of 3.0
Mobile. This way we won't have to specify -P tzmb_v3.0_arm64-wayland
-A aarch64 flag when using the script.

2. Changed the build_emulator.sh script for mobile and tv target

This patch add the target option into the build_emulator.sh script.
We can build the mobile and tv emulator using the below build command.

$ ./tizen_src/build/build_emulator.sh [mobile/tv]

3. Added the mirror server to improve the download speed in HQ

This patch added the mirror server which provided by platform team to
gbs.conf in order to improve the download speed in HQ.

$ ./tizen_src/build/build_mobile.sh -P tzmb_v3.0_arm64-wayland_mirror
$ ./tizen_src/build/build_tv.sh -P tztv_v3.0_arm-wayland_mirror

4. Disabled the rpmlint for arm64-wayland profile of Tizen 3.0 Mobile

To improve the build time for developers, this patch add the
arm64-wayland profile. Also the tztv_v3.0_arm-x11.conf and
tzmb_v3.0_arm-x11.conf were removed because platform team doesn't
support x11 profile.

5. Updated the README.md

Bug: http://web.sec.samsung.net/bugzilla/show_bug.cgi?id=13158
Reviewed by: Antonio Gomes, SeungSeop Park

Change-Id: I1153a50efe3aaeb0c48bd5962c4267df32f0aa64
Signed-off-by: Youngcheol Kang <ychul.kang@samsung.com>