FIOM bit missing from MENVCFG mask

[vmoya-smd]

The mask defined when MEMVCFG CSR is created doesn't include the FIOM field (bit 0).

const reg_t menvcfg_mask = (proc->extension_enabled(EXT_ZICBOM) ? MENVCFG_CBCFE | MENVCFG_CBIE : 0) | (proc->extension_enabled(EXT_ZICBOZ) ? MENVCFG_CBZE : 0) | (proc->extension_enabled(EXT_SMNPM) ? MENVCFG_PMM : 0) | (proc->extension_enabled(EXT_SVADU) ? MENVCFG_ADUE: 0) | (proc->extension_enabled(EXT_SVPBMT) ? MENVCFG_PBMTE : 0) | (proc->extension_enabled(EXT_SSTC) ? MENVCFG_STCE : 0) | (proc->extension_enabled(EXT_ZICFILP) ? MENVCFG_LPE : 0) | (proc->extension_enabled(EXT_ZICFISS) ? MENVCFG_SSE : 0) | (proc->extension_enabled(EXT_SSDBLTRP) ? MENVCFG_DTE : 0); menvcfg = std::make_shared<envcfg_csr_t>(proc, CSR_MENVCFG, menvcfg_mask, 0);

MENVCFG_FIOM should be added to the mask.

[aswaterman]

Likewise henvcfg and senvcfg. Could you submit a PR?