On 32-bit hosts, UBSan reports:

====================================================================
UBSAN: Undefined behaviour in ./arch/sandbox/board/hostfile.c:135:12
shift exponent 32 is too large for 32-bit type 'long unsigned int'
====================================================================

Fix this by using a unsigned long long for base. The upper 32-bit
won't be set, but device tree fixups can now read them.

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>