ARM: 8924/1: tcm: make dtcm_end and itcm_end static

The dtcm_end and itcm_end are not exported or used
elsewhere, so make them static to remove the following
sparse warnign:

arch/arm/kernel/tcm.c:33:5: warning: symbol 'dtcm_end' was not declared. Should it be static?
arch/arm/kernel/tcm.c:34:5: warning: symbol 'itcm_end' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>