target/alpha: Make get_phys_page_debug handle non-page-aligned addrs

Currently our implementations of SysemuCPUOps::get_phys_page_debug
and SysemuCPUOps::get_phys_page_attrs_debug are a mix of "accepts a
non-page-aligned virtual address and returns the corresponding
non-page-aligned physical address" and "only returns a page-aligned
physical address".  This is awkward for callsites, which in practice
all want the physical address for an arbitrary virtual address and
have to work around the possibility of getting a page-aligned
address, and it doesn't account for protection being possibly on a
sub-page-sized granularity.  We want to standardize on the
implementation having to handle non-page-aligned addresses.

For alpha, the get_physical_address() function accepts arbitrary
input addresses but may return an output rounded down to a page
boundary, so in alpha_cpu_get_phys_page_debug() we OR the within-page
offset into it before returning it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20260417173105.1648172-3-peter.maydell@linaro.org
Message-ID: <20260430093810.2762539-4-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>