[ARM] 3621/1: fix compilation breakage for pnx4008

Patch from Vitaly Wool

pnx4008_defconfig fails to build:

include/asm/hardware/debug-8250.S: Assembler messages:
include/asm/hardware/debug-8250.S:12: Error: Macro with this name was already defined.

This is due to senduart macro erroneously defined in include/asm-arm/arch-pnx4008/debug-macro.S. This patch removes it from that file.

Signed-off-by: Vitaly Wool <vwool@ru.mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>