ARM: dts: msm: Remove blsp1_uart2 device from msm8992

The blsp1_uart2 device is no longer needed on msm8992,
since all 8992 platforms are currently using blsp1_uart5.
Furthermore, the naming of this device was inaccurate.

Change-Id: I79ad8ec8149b0b8c54132c815355e3f9a3c08734
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>