ggml: riscv: add riscv spacemit backend (llama/15288)

ggml: riscv: add riscv spacemit backend (llama/15288)

* ggml: add spacemit backend

Change-Id: I249bdc043485d815a9c351867137bc1e27cc2e23

* add new line at end of file

Change-Id: I889ed1c85fb45e62350ecde0c06f70450cadfbe2

* add riscv zba extension limit

Change-Id: I321eb200f859751727afe5cae13074dfce2bb0ce

* fixed for review comments, file renamed and format

Change-Id: Ia20b6ec24a36638e62e0fe07cf100916a7cce3ce

* fixed for code format, after clang-format

Change-Id: I5dc33a0412da3d3f2d77075d8939185d3009eca2

* use _Float16 instead of __fp16

Change-Id: I039fb02bb95270e641bc4442204e658735859d43

* add ci for riscv64-spacemit-ime-native

Change-Id: I711c1033061df1a289ea77891b2997599dfe8279

* update debian-13-riscv64-spacemit-ime-native ci label

Change-Id: Ifb2b891e2fca57b5da604fce2ac255f27731179a

* remove license comment for spacemit ime

Change-Id: If0dc3ca30a958631ccca0a28b62e0b825f9fb0c3

* upgrade binutils for gcc ime

Change-Id: Ibf2fa74c1064408974cb5b45f044d40987e5fb45

* add spacemit ime cross jobs

Change-Id: I80d74909941d41cb9cd09e51d8baf01c985cbfc6

* remove native compile for riscv64-spacemit-ime

Change-Id: I01920afafdc73fa7424014fd648d243f8ec9e25e

* ci : add caching for spacemit ime cross toolchain

Change-Id: Ic54a192019a2fd982bbd58225ce3bbc38f4053de

* ci: bug fixed for cache path and env

Change-Id: I28c42e10b6fff053bb6580926ca2353448cb042a

* Update .github/workflows/build-linux-cross.yml for cache path

Co-authored-by: Sigbjørn Skjæret <redacted>
* bugfixed for  build-linux-cross.yml,  syntax error

Co-authored-by: Sigbjørn Skjæret <redacted>
---------

Co-authored-by: cailinxi <redacted>
Co-authored-by: Sigbjørn Skjæret <redacted>