ARM: hyp-stub: Fix Thumb-2 compilation

The assembler defaults to emiting the short form of ADR, leading
to an out-of-range immediate. Using the wide version solves this
issue.

Fixes: bc845e4f ("ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init code")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>