sifive_e: Rename memmap enum constants

Some of the enum constant names conflict with a QOM type check
macro (SIFIVE_E_PRCI).  This needs to be addressed to allow us to
transform the QOM type check macros into functions generated by
OBJECT_DECLARE_TYPE().

Rename all the constants to SIFIVE_E_DEV_*, to avoid conflicts.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20200911173447.165713-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>