ARM: davinci: remove test for undefined Kconfig macro

The DaVinci debugging macro contains a check for
CONFIG_DEBUG_DAVINCI_DA8XX_UART0. But there's no corresponding Kconfig
symbol, so this test will always evaluate to false. That Kconfig symbol
is not needed because, as __arch_decomp_setup() shows, there are no
DaVinci DA8XX boards that use UART0 for debugging. We can remove two
lines of unneeded code.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>