TQM8xx: make room for growing code size due to I/O accessor cleanup

Commit "PPC: Cleanup tqm8xx_pcmcia.c" will clean up the PCMCIA code
to use I/O accessors instead of plain volatile pointer accesses.
This will result in about 300 byte bigger code.  Fix custom linker
script to make room for this.

While we are at it, drop unmaintained u-boot.lds.debug linker script.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Marek Vasut <marek.vasut@gmail.com>
Tested-by: Wolfgang Denk <wd@denx.de>