omap4430: force hardware breakpoints for GDB

Soft breakpoints are currently broken if the MMU is enabled due to incorrect
cache flushing.  Until this is fixed, force the use of hardware breakpoints.

Signed-off-by: Aaron Carroll <aaronc@ok-labs.com>

tcl/target/omap4430.cfg

@@ -109,3 +109,6 @@ $_TARGETNAME configure -event reset-assert "$_TARGETNAME mww phys $PRM_RSTCTRL 0
 $_CHIPNAME.m30 configure -event reset-assert { }
 $_CHIPNAME.m31 configure -event reset-assert { }
 
+# Soft breakpoints don't currently work due to broken cache handling
+gdb_breakpoint_override hard
+