target/ppc: Rename access_type to type in mmu_helper.c

The variable that holds ACCESS_INT, ACCESS_FLOAT, etc is
variously called 'int type' or 'int access_type' within
this file.  Standardize on 'int type' throughout.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210518201146.794854-6-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>