tests/functional: Bump some arm test timeouts

tests/functional: Bump some arm test timeouts

On my local machine, for a debug build, sbsaref_alpine takes
nearly 900s:

$ (cd build/x86 && ./pyvenv/bin/meson test --setup thorough --suite func-thorough func-aarch64-aarch64_sbsaref_alpine
)

1/1 qemu:func-thorough+func-aarch64-thorough+thorough / func-aarch64-aarch64_sbsaref_alpine
                      OK 896.90s

arm_aspeed_rainier can also run close to its current timeout:
 6/44 qemu:func-thorough+func-arm-thorough+thorough / func-arm-arm_aspeed_rainier
                      OK 215.75s

and arm_aspeed_ast2500 and arm_aspeed_ast2600 can go over:
13/44 qemu:func-thorough+func-arm-thorough+thorough / func-arm-arm_aspeed_ast2600
                      OK 792.94s

27/44 qemu:func-thorough+func-arm-thorough+thorough / func-arm-arm_aspeed_ast2500
                 TIMEOUT 480.01s

The sx1 test fails not on the overall meson timeout but on the
60 second timeout in some of the subtests.

Bump all these timeouts up a bit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20250221140640.786341-1-peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>