eal/windows: add missing stdint include

eal/windows: add missing stdint include

Following the addition of the in_addr/in6_addr structs
to in.h the header file must have stdint.h included
for the definitions of the uint8_t/uint32_t types used
within the new structs.

Not having it could results in the following errors
in places where in.h is included:

in.h:30:2: error: unknown type name 'uint32_t'
        uint32_t s_addr;

in.h:34:2: error: unknown type name 'uint8_t'
        uint8_t s6_addr[16];

Fixes: f40a74cfcf0 ("eal/windows: improve compatibility networking headers")

Signed-off-by: Tal Shnaiderman <talshn@nvidia.com>
Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>